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RockyLinux 8.4 ; Installing a mail server

1.Install Postfix and Dovecot

1-1.Install the required software.

Check if Postfix is installed.
Check for sasl-related packages
Register Postfix to the service.

1-2.Preparation for user registration

①Prep for new users.
Set up the system to automatically send and receive emails when a new user is added.

➁Preparing the email environment for existing users
Configure the settings so that the user you have already created (user [tama] in the example) can send and receive mail.

1-3.Editing the Postfix Configuration File

①Editing the SMTP Authentication Configuration File
Back up the SMTP authentication configuration file

➁Registering the saslauthd service

Start saslauthd

➂Creating a sample Postfix user
This time, as an example, the user [rocky].

The password you set will be used for receiving mail (POP)

Setting the SMTP-AUTH Password

Check the registered user and change the group permissions in /etc/sasldb2 so that postfix can read it
Change to the postfix group、

④Editing the Postfix Configuration File

⑤Configure the submission port (port 587)

⑥Start Postfix.

1-4.Edit the Dovecot configuration file

①Edit the dovecot.conf file
Back up the dovecot.conf file

➁Edit the 10-ssl.conf file

➂Register dovecot as a service and start it.

2.Postfix + Clamav + Amavisd

①Install Amavisd and Clamav Server

➁Edit configuration file

➂Configure and start Amavisd

④Postfix Configuration

3.Anti-spam settings

①Install SpamAssassin to prevent spam.

➁Configuring SpamAssassin

➂Install a script to update the SpamAssassin configuration file.

④Grant execute permission to the spamassassin-update script and run it.

Make sure that the SpamAssassin configuration file is created in the /etc/mail/spamassassin directory on the current date.

directory as of the current date.

⑤Configuring Postfix to incorporate SpamAssassin
⑥Edit the /etc/postfix/ file
Restart postfix.