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Sie können zwar ein SSL-Zertifikat über eine beliebige Zertifizierungsstelle generieren, wir empfehlen jedoch die Verwendung von Certbot, um schnell und einfach ein kostenloses Zertifikat zu generieren.  
Sie können zwar ein SSL-Zertifikat über eine beliebige Zertifizierungsstelle generieren, wir empfehlen jedoch die Verwendung von Certbot, um schnell und einfach ein kostenloses Zertifikat zu generieren.  
* Befolgen Sie diese [https://certbot.eff.org/instructions Certbot-Anleitung] und wählen Sie Ihre Linux-Distribution und Webserver-Software (oder "None", wenn dieser Server nur als Mailserver fungiert).  
* Befolgen Sie diese [https://certbot.eff.org/instructions Certbot-Anleitung] und wählen Sie Ihre Linux-Distribution und Webserver-Software (oder "None", wenn dieser Server nur als Mailserver fungiert).  
* Nach der Installation führen Sie Certbot mit der Option certonly aus und geben Sie den FQDN-Namen Ihres Mailservers ein (z. B. ''mail.example.com''):
* Nach der Installation führen Sie Certbot mit der Option certonly aus und geben Sie den FQDN-Namen Ihres Mailservers ein (beispielsweise ''mail.example.com''):


  # certbot certonly --standalone
  # certbot certonly --standalone
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=== Datenbank ===
=== Datenbank ===
Die Daten für die Benutzer (E-Mail-Adressen), Domänen und Aliasnamen des Mailservers werden in einer MySQL- (oder MariaDB-) Datenbank gespeichert.
siehe [[E-Mail/Server/Setup:Datenbank]]
* Sowohl Dovecot als auch Postfix interagieren mit diesen Daten.
 
Führen Sie die folgenden Schritte aus, um die Datenbank zu erstellen und Tabellen für virtuelle Benutzer, Domänen und Aliase hinzuzufügen:
 
# Verwenden Sie das Tool [https://mariadb.com/kb/en/library/mysql_secure_installation/ mysql_secure_installation], um zusätzliche Sicherheitsoptionen zu konfigurieren.
* Dieses Tool wird Sie fragen, ob Sie ein neues Passwort für den MySQL-Root-Benutzer festlegen wollen, aber Sie können diesen Schritt überspringen:
# mysql_secure_installation
 
;Antworten Sie '''Y''' auf die folgenden Fragen
* Remove anonymous users?
* Disallow root login remotely?
* Remove test database and access to it?
* Reload privilege tables now?
 
; Log in to MySQL as a root user
# mysql -u root -p
 
; Create a new database
CREATE DATABASE mailserver;
 
; Create the MySQL user and grant the new user permissions over the database.
Replace password with a secure password for ''mailuser''
CREATE USER 'mailuser'@'127.0.0.1' IDENTIFIED BY 'password';
GRANT SELECT ON mailserver.* TO 'mailuser'@'127.0.0.1';
# Run FLUSH to reload the MySQL database and apply the change:
FLUSH PRIVILEGES;
 
; Switch to the new mailserver database:
USE mailserver;
 
; Create a table for the domains that will receive mail
CREATE TABLE `virtual_domains` (
  `id` int(11) NOT NULL auto_increment,
  `name` varchar(50) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
 
; Create a table for all of the email addresses and passwords
CREATE TABLE `virtual_users` (
  `id` int(11) NOT NULL auto_increment,
  `domain_id` int(11) NOT NULL,
  `password` varchar(106) NOT NULL,
  `email` varchar(100) NOT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `email` (`email`),
  FOREIGN KEY (domain_id) REFERENCES virtual_domains(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
 
; Create a table for the email aliases:
CREATE TABLE `virtual_aliases` (
  `id` int(11) NOT NULL auto_increment,
  `domain_id` int(11) NOT NULL,
  `source` varchar(100) NOT NULL,
  `destination` varchar(100) NOT NULL,
  PRIMARY KEY (`id`),
  FOREIGN KEY (domain_id) REFERENCES virtual_domains(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
 
==== Adding a Domain within MySQL ====
; Verify that you are still logged into the MySQL shell.
If not, run
# mysql -u root -p to access MySQL.
 
; Add the domains to the virtual_domains table.
* Replace the values for example.com and hostname with your own settings:
INSERT INTO mailserver.virtual_domains (name) VALUES ('example.com');
 
; Verify the alias was added correctly by running a SELECT query on the virtual_domains table.
* Make a note of the corresponding id next to the domain as this will be used when adding emails and aliases.
SELECT * FROM mailserver.virtual_domains;
 
If needed, repeat this process to add another domain.
 
==== Adding an Email Address within MySQL ====
# If you are still logged in to MySQL, return to your main Linux shell by typing exit and hitting enter.
# Generate a hash using the SHA512-CRYPT encryption scheme by running the command below, replacing password with the password you’d like to use for the email user.
# doveadm pw -s SHA512-CRYPT -p "password" -r 5000
The output will look similar to {SHA512-CRYPT}$6$hvEwQ....
* Copy this output, ignoring the first 14 characters of ''{SHA512-CRYPT}''.
* Since the SHA512-CRYPT scheme was used, the password should start with ''$6$''.
# Log back into MySQL as the root user:
# mysql -u root -p
# Add the email address and password hash to the virtual_users table.
* The domain_id value (currently set to '1') references the virtual_domain table’s id value.
* If you added more than one domain, replace this value to correspond with the desired domain.
* Replace user@example.com with the email address that you wish to configure on the mail server.
* Replace hash with password hash generated in a previous step.
INSERT INTO mailserver.virtual_users (domain_id, password , email) VALUES ('1', 'hash', 'user@example.com');
# Verify the email was added correctly by running a SELECT query on the virtual_users table.
SELECT * FROM mailserver.virtual_users;
# If needed, repeat this process to add another email address.
 
Alternatively, the password hash can be generated directly within the MySQL INSERT statement above by replacing 'hash' (deleting the single quote characters as well) with one of the following:* Using the [https://dev.mysql.com/doc/refman/5.7/en/encryption-functions.html#function_encrypt ENCRYPT()] function: ENCRYPT('password', CONCAT('$6$', SUBSTRING(SHA(RAND()), -16))), replacing password with the plain text password desired for the email user.
* This function has been removed from MySQL 5.8 and above.
* Using the [https://dev.mysql.com/doc/refman/8.0/en/encryption-functions.html#function_sha2 SHA2()] function: TO_BASE64(UNHEX(SHA2('password', 512))), replacing password with the plain text password desired for the email user.
* This function generates the hash in a slightly different scheme.
* When configuring the Dovecot MYSQL settings (/etc/dovecot/dovecot-sql.conf.ext) in this guide, set default_pass_scheme to SHA512 instead of SHA512-CRYPT.
 
==== Adding an Alias within MySQL ====
 
; An email alias forwards all emails it receives to another email address.
While not required, you can follow the steps below to add an email alias.
 
; Verify that you are still logged into the MySQL shell.
* If not, run 
# mysql -u root -p to access MySQL.
 
; Add the alias to the virtual_aliases table.
* The domain_id value (currently set to '1') references the virtual_domain table’s id value.
* If you added more than one domain, replace this value to correspond with the desired domain.
* Replace alias@example.com with the desired alias.
* Replace user@example.com with the email address that you wish to forward email to.
INSERT INTO mailserver.virtual_aliases (domain_id, source, destination) VALUES ('1', 'alias@example.com', 'user@example.com');
 
; Verify the alias was added correctly by running a SELECT query on the virtual_aliases table.
SELECT * FROM mailserver.virtual_aliases;
 
If needed, repeat this process to add another email alias.


=== Postfix ===
=== Postfix ===
Postfix is a ''Mail Transfer Agent'' (MTA) that relays mail between your Server and the internet.
siehe [[E-Mail/Server/Setup:Postfix]]
* It is highly configurable, allowing for great flexibility.
* This guide maintains many of Posfix’s default configuration values.
 
==== How Do Postfix And Dovecot Work Together? ====
Postfix and Dovecot work together to help make email servers function as intended (sending and receiving email) and accessible to whichever email client the end user wishes to use.
* While Postfix manages email delivery and receipt, Dovecot allows email clients to connect to these emails when we want to read them.
 
==== Configuration File Settings for Postfix Email Server ====
The main.cf file is the primary configuration file used by Postfix.
# If you are still logged in to MySQL, return to your main Linux shell by typing exit and hitting enter.
# Make a copy of the default Postfix configuration file in case you need to revert to the default configuration:
# cp /etc/postfix/main.cf /etc/postfix/main.cf.orig
# Edit the /etc/postfix/main.cf file, replacing any occurrences of example.com with your domain name and verifying that the paths to the SSL certificate and private key are correct.
 
* Here is an example file that can be used:
; /etc/postfix/main.cf
# See /usr/share/postfix/main.cf.dist for a commented, more complete version
# Debian specific:  Specifying a file name will cause the first
# line of that file to be used as the name.  The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
# appending .domain is the MUA's job.
append_dot_mydomain = no
# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
readme_directory = no
# See http://www.postfix.org/COMPATIBILITY_README.html -- default to 2 on
# fresh installs.
compatibility_level = 2
# TLS parameters
smtpd_tls_cert_file=/etc/letsencrypt/live/example.com/fullchain.pem
smtpd_tls_key_file=/etc/letsencrypt/live/example.com/privkey.pem
smtpd_use_tls=yes
smtpd_tls_auth_only = yes
smtp_tls_security_level = may
smtpd_tls_security_level = may
smtpd_sasl_security_options = noanonymous, noplaintext
smtpd_sasl_tls_security_options = noanonymous
# Authentication
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.
# Restrictions
smtpd_helo_restrictions ==
  permit_mynetworks,
  permit_sasl_authenticated,
  reject_invalid_helo_hostname,
  reject_non_fqdn_helo_hostname
smtpd_recipient_restrictions ==
  permit_mynetworks,
  permit_sasl_authenticated,
  reject_non_fqdn_recipient,
  reject_unknown_recipient_domain,
  reject_unlisted_recipient,
  reject_unauth_destination
smtpd_sender_restrictions ==
  permit_mynetworks,
  permit_sasl_authenticated,
  reject_non_fqdn_sender,
  reject_unknown_sender_domain
smtpd_relay_restrictions ==
  permit_mynetworks,
  permit_sasl_authenticated,
  defer_unauth_destination
# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.
myhostname = example.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mydomain = example.com
myorigin = $mydomain
mydestination = localhost
relayhost ==
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all
# Handing off local delivery to Dovecot's LMTP, and telling it where to store mail
virtual_transport = lmtp:unix:private/dovecot-lmtp
# Virtual domains, users, and aliases
virtual_mailbox_domains = mysql:/etc/postfix/mysql-virtual-mailbox-domains.cf
virtual_mailbox_maps = mysql:/etc/postfix/mysql-virtual-mailbox-maps.cf
virtual_alias_maps = mysql:/etc/postfix/mysql-virtual-alias-maps.cf,
  mysql:/etc/postfix/mysql-virtual-email2email.cf
# Even more Restrictions and MTA params
disable_vrfy_command = yes
strict_rfc821_envelopes = yes
#smtpd_etrn_restrictions = reject
#smtpd_reject_unlisted_sender = yes
#smtpd_reject_unlisted_recipient = yes
smtpd_delay_reject = yes
smtpd_helo_required = yes
smtp_always_send_ehlo = yes
#smtpd_hard_error_limit = 1
smtpd_timeout = 30s
smtp_helo_timeout = 15s
smtp_rcpt_timeout = 15s
smtpd_recipient_limit = 40
minimal_backoff_time = 180s
maximal_backoff_time = 3h
# Reply Rejection Codes
invalid_hostname_reject_code = 550
non_fqdn_reject_code = 550
unknown_address_reject_code = 550
unknown_client_reject_code = 550
unknown_hostname_reject_code = 550
unverified_recipient_reject_code = 550
unverified_sender_reject_code = 550
 
The main.cf file declares the location of virtual_mailbox_domains, virtual_mailbox_maps, and virtual_alias_maps files.
*These files contain the connection information for the MySQL lookup tables created in the [https://www.linode.com/docs/guides/email-with-postfix-dovecot-and-mysql/#mysql MySQL] section of this guide.
*Postfix will use this data to identify all domains, corresponding mailboxes, and valid users.
 
; Create the file for virtual_mailbox_domains.
Replace the value for password with your database user’s password.
* If you used a different name for your database user and dbname replace those with your own values:
 
;/etc/postfix/mysql-virtual-mailbox-domains.cf
user = mailuser
password = mailuserpass
hosts = 127.0.0.1
dbname = mailserver
query = SELECT 1 FROM virtual_domains WHERE name='%s'
 
; Create the /etc/postfix/mysql-virtual-mailbox-maps.cf file
enter the following values.
* Use the database user’s password and make any other changes as needed:
 
; /etc/postfix/mysql-virtual-mailbox-maps.cf
user = mailuser
password = mailuserpass
hosts = 127.0.0.1
dbname = mailserver
query = SELECT 1 FROM virtual_users WHERE email='%s'
 
; Create the /etc/postfix/mysql-virtual-alias-maps.cf file
enter the following values.
* Use the database user’s password and make any other changes as needed:
 
; /etc/postfix/mysql-virtual-alias-maps.cf
user = mailuser
password = mailuserpass
hosts = 127.0.0.1
dbname = mailserver
query = SELECT destination FROM virtual_aliases WHERE source='%s'
 
; Create the /etc/postfix/mysql-virtual-email2email.cf file
enter the following values.
* Use the database user’s password and make any other changes as needed:
 
; /etc/postfix/mysql-virtual-email2email.cf
user = mailuser
password = mailuserpass
hosts = 127.0.0.1
dbname = mailserver
query = SELECT email FROM virtual_users WHERE email='%s'
 
; Restart Postfix
# systemctl restart postfix
 
==== Testing Postfix ====
We can test the Postfix configuration by using the postmap command, which can query Postfix’s lookup tables.# Enter the following command to ensure that Postfix can query the virtual_domains table.
* Replace example.com with the first name value.
* The command should return 1 if it is successful:
# postmap -q example.com mysql:/etc/postfix/mysql-virtual-mailbox-domains.cf
# Test Postfix to verify that it can retrieve the first email address from the MySQL table virtual_users.
* Replace email1@example.com with the first email address added to the table.
* You should receive 1 as the output:
# postmap -q email1@example.com mysql:/etc/postfix/mysql-virtual-mailbox-maps.cf
# Test Postfix to verify that it can query the virtual_aliases table.
* Replace alias@example.com with the first source value created in the table.
* The command should return the destination value for the row:
# postmap -q alias@example.com mysql:/etc/postfix/mysql-virtual-alias-maps.cf
 
==== Master Program Settings ====
* Postfix’s master program starts and monitors all of Postfix’s processes.
* The configuration file master.cf lists all programs and information on how they should be started.
 
Make a copy of the /etc/postfix/master.cf file:
# cp /etc/postfix/master.cf /etc/postfix/master.cf.orig
 
; Edit /etc/postfix/master.cf to contain the values in the excerpt below.
The rest of the file can remain unchanged
 
#  File: /etc/postfix/master.cf
#
# Postfix master process configuration file.  For details on the format
# of the file, see the master(5) manual page (command: "man 5 master" or
# on-line: http://www.postfix.org/master.5.html).
#
# Do not forget to execute "postfix reload" after editing this file.
#
# ==========================================================================
# service type  private unpriv  chroot  wakeup  maxproc command + args
#              (yes)  (yes)  (yes)    (never) (100)
# ==========================================================================
smtp      inet  n      -      n      -      -      smtpd
#smtp      inet  n      -      -      -      1      postscreen
#smtpd    pass  -      -      -      -      -      smtpd
#dnsblog  unix  -      -      -      -      0      dnsblog
#tlsproxy  unix  -      -      -      -      0      tlsproxy
submission inet n      -      y      -      -      smtpd
  -o syslog_name=postfix/submission
  -o smtpd_tls_security_level=encrypt
  -o smtpd_sasl_auth_enable=yes
  -o smtpd_sasl_type=dovecot
  -o smtpd_sasl_path=private/auth
  -o smtpd_reject_unlisted_recipient=no
  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
  -o milter_macro_daemon_name=ORIGINATING
smtps    inet  n      -      -      -      -      smtpd
  -o syslog_name=postfix/smtps
  -o smtpd_tls_wrappermode=yes
  -o smtpd_sasl_auth_enable=yes
  -o smtpd_sasl_type=dovecot
  -o smtpd_sasl_path=private/auth
  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
  -o milter_macro_daemon_name=ORIGINATING
[...]
 
; Change the permissions
of the /etc/postfix directory to restrict permissions to allow only its owner and the corresponding group
# chmod -R o-rwx /etc/postfix
 
; Restart Postfix:
# systemctl restart postfix


=== Dovecot ===
=== Dovecot ===
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=== Testing  ===
=== Testing  ===
# To send and receive test emails to your mail server, install the Mailutils package:
siehe [[E-Mail/Server/Setup:Testing]]
# apt-get install mailutils
# Send a test email to an email address outside of your mail server, like a Gmail account.
* Replace email1@example.com with an email address from your mail server:
echo "Email body text" |  # mail -s "Email subject line" recipient@gmail.com -aFrom:email1@example.com
# Log in to the test email account and verify that you have received the email from the specified mail server email address.
# Send a test email to your mail server from an outside email address.
* Log back in and check that the email was received; substitute in the username and domain you sent the mail to:
# mail -f /var/mail/vhosts/example.com/email1
When prompted, enter the number corresponding to the email you would like to view:
"/var/mail/vhosts/example.com/": 9 messages 5 new 4 unread
U  1 John Doe    Wed Jun 27 16:00  57/2788  Test email 1
U  2 John Doe    Wed Jun 27 16:02  56/2761  Test email 2
U  3 John Doe    Wed Jun 27 16:35  15/594  Test email 3
U  4 John Doe    Wed Jun 27 16:42  71/3535  Test email 4
>N  5 John Doe    Mon Jul  2 10:55  13/599  Subject of the Email
?
 
The email message header and body should display.
* Consider adding spam and virus filtering and a webmail client.
See [https://www.linode.com/docs/guides/troubleshooting-problems-with-postfix-dovecot-and-mysql/ Troubleshooting problems with Postfix, Dovecot, and MySQL] for debugging steps.


=== Configuring an Email Client ===
=== Configuring an Email Client ===
You can set up an email client to connect to your mail server.  
You can set up an email client to connect to your mail server.  
* Many clients detect server settings automatically.  
* Many clients detect server settings automatically.  
* Manual configuration requires the following parameters:
 
Manual configuration requires the following parameters:
* '''Username:''' An email address that was configured (ex: [mailto:user@example.com user@example.com]).
* '''Username:''' An email address that was configured (ex: [mailto:user@example.com user@example.com]).
* '''Password:''' The password configured for that email.
* '''Password:''' The password configured for that email.
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  '''Note'''
  '''Note'''
  The Thunderbird email client will sometimes have trouble automatically detecting account settings when using Dovecot.  
  The Thunderbird email client will sometimes have trouble automatically detecting account settings when using Dovecot.  
* After it fails to detect the appropriate account settings, you can set up your email account manually.  
* After it fails to detect the appropriate account settings, you can set up your email account manually.  
* Add in the appropriate information for each setting, using the above values, leaving no setting on '''Auto''' or '''Autodetect'''.  
* Add in the appropriate information for each setting, using the above values, leaving no setting on '''Auto''' or '''Autodetect'''.  
* Once you have entered all the information about your mail server and account, press '''Done''' rather '''Re-Test''' and Thunderbird should accept the settings and retrieve your mail.
* Once you have entered all the information about your mail server and account, press '''Done''' rather '''Re-Test''' and Thunderbird should accept the settings and retrieve your mail.


=== Managing Spam ===
=== Spam ===
; SpamAssassin
siehe [[E-Mail/Server/Setup:Spam]]
 
[https://spamassassin.apache.org/ Apache SpamAssassin] is a free and open source platform that allows us to find and filter out spam email.
* This software is commonly used in tandem with Postfix and Dovecot.
 
;Install SpamAssassin
# apt-get install spamassassin spamc
 
; Create a user for SpamAssassin daemon(spamd):
# adduser spamd --disabled-login
 
;Edit the /etc/default/spamassassin configuration file.
Set the home directory, update the OPTIONS parameter with the user that was just created (as well as the home directory), and update the CRON parameter to 1.
 
File: /etc/default/spamassassin
[...]
HOMEDIR="/home/spamd/"
OPTIONS="--create-prefs --max-children 5 --username spamd --helper-home-dir ${HOMEDIR} -s ${HOMEDIR}spamd.log"
PIDFILE="${HOMEDIR}spamd.pid"
[...]
CRON=1
 
Here is a [https://spamassassin.apache.org/full/3.1.x/doc/Mail_SpamAssassin_Conf.html detailed documentation] of SpamAssassin’s configuration file that you can refer to while working through these next steps.
 
; Configure the Postfix email server to check each email with a score > 5.0, mark it as '''''SPAM''''', and send it directly to the junk folder.
* Add or adjust the following lines inside /etc/spamassassin/local.cf to setup your anti-spam rules:
 
*  File: /etc/spamassassin/local.cf
 
{|
|-
|| 
|| ...
 
rewrite_header Subject ***** SPAM _SCORE_ *****
report_safe            0
required_score          5.0
use_bayes              1
use_bayes_rules        1
bayes_auto_learn        1
skip_rbl_checks        0
use_razor2              0
use_dcc                0
use_pyzor              0
 
...
|-
|}
* Set up your Postfix email server to allow anti-spam configuration to check incoming emails.
* Edit /etc/postfix/master.cf and add a filter:
 
#  File: /etc/postfix/master.cf
 
{|
|-
|| 
|| ...
 
smtp      inet  n      -      -      -      -      smtpd
-o content_filter=spamassassin
 
...
 
spamassassin unix -    n      n      -      -      pipe
user=spamd argv=/usr/bin/spamc -f -e
/usr/sbin/sendmail -oi -f ${sender} ${recipient}
|-
|}
# Start Spamassassin and enable the service to start on boot:
# systemctl start spamassassin
# systemctl enable spamassassin
If not using systemd (as is the case with Debian 7 and earlier), edit the /etc/default/spamassassin configuration file instead.
* Set the ENABLED parameter to 1.
# Restart the Postfix email server to get your new anti-spam settings in place:
# systemctl restart postfix


== Konfiguration ==
== Konfiguration ==
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== Siehe auch ==
== Siehe auch ==
== Links ==
== Links ==
=== Projekt-Homepage ===
=== Projekt ===
=== Weblinks ===
=== Weblinks ===
# https://www.linode.com/docs/guides/email-with-postfix-dovecot-and-mysql/
# https://www.linode.com/docs/guides/email-with-postfix-dovecot-and-mysql/
# [https://www.linode.com/docs/guides/troubleshooting-problems-with-postfix-dovecot-and-mysql/ Troubleshooting Problems with Postfix, Dovecot, and MySQL]
# [https://www.linode.com/docs/guides/troubleshooting-problems-with-postfix-dovecot-and-mysql/ Troubleshooting Problems with Postfix, Dovecot, and MySQL]
# [http://www.postfix.org/BASIC_CONFIGURATION_README.html Postfix Basic Configuration]
# [https://www.postfix.org/BASIC_CONFIGURATION_README.html Postfix Basic Configuration]
# [http://www.postfix.org/SASL_README.html Postfix SASL Howto]
# [https://www.postfix.org/SASL_README.html Postfix SASL Howto]
# [https://wiki2.dovecot.org/ Dovecot Wiki]
# [https://wiki2.dovecot.org/ Dovecot Wiki]


=== Einzelnachweise ===
<references />
== Testfragen ==
<div class="toccolours mw-collapsible mw-collapsed">
''Testfrage 1''
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[[Kategorie:Entwurf]]
 
[[Kategorie:E-Mail:Server]]
 
[[Kategorie:E-Mail/Server]]
[[Kategorie:Postfix]]
[[Kategorie:Postfix]]
[[Kategorie:Dovecot]]
[[Kategorie:Dovecot]]

Aktuelle Version vom 28. April 2025, 10:35 Uhr

E-Mail-Server-Setup mit Postfix, Dovecot und MySQL

Beschreibung

Konfiguration eines E-Mail-Servers mit Postfix, Dovecot und MySQL

  1. DNS konfigurieren
  2. Datenbank einrichten
  3. Postfix installieren und einrichten
  4. Dovecot installieren und einrichten
  5. Testen des E-Mail-Server
  6. Weitere Domänen und E-Mail-Adressen hinzuzufügen

Voraussetzungen

  1. Linux-Server mit geeigneten Sicherheitsmaßnahmen

DNS konfigurieren

Wenn Sie bereit sind, das DNS zu aktualisieren und mit dem Senden von E-Mails an den Server zu beginnen, bearbeiten Sie die DNS-Einträge der Domäne, um Ihren E-Mail-Server zu definieren:

  • Fügen Sie einen DNS-Eintrag für Ihren E-Mail-Server hinzu
  • Dies kann entweder ein A-Eintrag sein, der auf die IP-Adresse Ihres Servers verweist, oder ein CNAME-Eintrag, der auf einen Domänennamen verweist.
  • Unabhängig davon, welcher Eintrag gewählt wird, setzen Sie den Hostnamen/Namen auf Mail.
MX-Record

Setzen Sie den Hostnamen/Namen auf @, den Mailserver auf mail.example.com (ersetzen Sie example.com durch Ihren Domainnamen) und die Priorität auf 10.

Beispielausgabe
@ MX 10 mail.example.com.
mail A 192.0.2.0
  • Vergewissern Sie sich, dass der MX-Eintrag für alle Domänen und Subdomänen geändert wird, die E-Mails empfangen könnten.
  • Wenn Sie eine neue Domäne einrichten, können Sie diese Schritte vor der Konfiguration des Mailservers durchführen.

Aktualisieren der Hosts-Datei

Stellen Sie sicher, dass

  • die Hosts-Datei eine Zeile für die öffentliche IP-Adresse enthält
  • mit dem Fully Qualified Domain Name (FQDN) verbunden ist

Im folgenden Beispiel ist 192.0.2.0 die öffentliche IP-Adresse, mail ist der lokale Hostname, und mail.example.com ist der FQDN

/etc/hosts
127.0.0.1 localhost.localdomain localhost
192.0.2.0 mail.example.com mail

SSL-Zertifikat installieren

Sie müssen ein SSL-Zertifikat auf Ihrem Mailserver installieren, bevor Sie die Dovecot-Konfigurationsschritte abschließen.

  • Das SSL-Zertifikat authentifiziert die Identität des Mailservers gegenüber den Benutzern und verschlüsselt die übertragenen Daten zwischen dem Mail-Client des Benutzers und dem Mailserver.

Sie können zwar ein SSL-Zertifikat über eine beliebige Zertifizierungsstelle generieren, wir empfehlen jedoch die Verwendung von Certbot, um schnell und einfach ein kostenloses Zertifikat zu generieren.

  • Befolgen Sie diese Certbot-Anleitung und wählen Sie Ihre Linux-Distribution und Webserver-Software (oder "None", wenn dieser Server nur als Mailserver fungiert).
  • Nach der Installation führen Sie Certbot mit der Option certonly aus und geben Sie den FQDN-Namen Ihres Mailservers ein (beispielsweise mail.example.com):
# certbot certonly --standalone

Sie können auch die Anleitung Install an SSL Certificate with Certbot zu Rate ziehen.

  • Notieren Sie sich die Dateipfade für das Zertifikat und den privaten Schlüssel.
  • Sie benötigen die Pfade für die Dovecot Konfigurationsschritte.

Install Packages

Update your system
# apt-get update
# apt-get upgrade
Install the packages
# apt-get install postfix postfix-mysql dovecot-core dovecot-imapd dovecot-pop3d dovecot-lmtpd dovecot-mysql mysql-server

Dadurch wird das Paket mysql-server installiert, das in einigen neueren Versionen von Debian nicht standardmäßig verfügbar ist.

  • Wenn Sie eine Meldung erhalten, dass das Paket nicht verfügbar ist, installieren Sie stattdessen mariadb-server.
  • MariaDB ist ein sofort einsetzbarer MySQL-Ersatz.

Bei neueren Versionen von MySQL werden Sie nicht aufgefordert, ein Passwort für den Root-MySQL-Benutzer einzugeben.

  • Das liegt daran, dass MySQL unter Debian und Ubuntu jetzt standardmäßig entweder das unix_socket- oder auth_socket-Autorisierungs-Plugin verwendet.
  • Dieses Autorisierungsschema erlaubt es Ihnen, sich mit dem Root-Benutzer der Datenbank anzumelden, solange Sie sich mit dem Linux-Root-Benutzer auf localhost verbinden.

Wenn Sie dazu aufgefordert werden, wählen Sie Internet Site als Typ des Mailservers, den das Postfix-Installationsprogramm konfigurieren soll.

  • Im nächsten Fenster sollte der System Mail Name auf die Domäne gesetzt werden, über die Sie E-Mails senden und empfangen möchten.

"Choose “Internet Site” for Postfix." "Set the system mail name for Postfix."

Datenbank

siehe E-Mail/Server/Setup:Datenbank

Postfix

siehe E-Mail/Server/Setup:Postfix

Dovecot

siehe Dovecot#Installation

Testing

siehe E-Mail/Server/Setup:Testing

Configuring an Email Client

You can set up an email client to connect to your mail server.

  • Many clients detect server settings automatically.

Manual configuration requires the following parameters:

  • Username: An email address that was configured (ex: user@example.com).
  • Password: The password configured for that email.
  • Server: (Both incoming and outgoing) A domain that resolves to the Server (such as mail.example.com)
  • IMAP: Set the port to 993 and the SSL/Security settings to SSL/TLS or equivalent.
  • POP3: If using POP3 instead of IMAP, set the port to 995 and require SSL.
  • SMTP: Set the port to 587 and the SSL/Security settings to STARTTLS or equivalent.
Note
The Thunderbird email client will sometimes have trouble automatically detecting account settings when using Dovecot.
  • After it fails to detect the appropriate account settings, you can set up your email account manually.
  • Add in the appropriate information for each setting, using the above values, leaving no setting on Auto or Autodetect.
  • Once you have entered all the information about your mail server and account, press Done rather Re-Test and Thunderbird should accept the settings and retrieve your mail.

Spam

siehe E-Mail/Server/Setup:Spam

Konfiguration

Dateien

Sicherheit

Siehe auch

Links

Projekt

Weblinks

  1. https://www.linode.com/docs/guides/email-with-postfix-dovecot-and-mysql/
  2. Troubleshooting Problems with Postfix, Dovecot, and MySQL
  3. Postfix Basic Configuration
  4. Postfix SASL Howto
  5. Dovecot Wiki
Abgerufen von „https://wiki.foxtom.de/index.php?title=E-Mail/Server/Setup&oldid=139135“