User-specific SpamAssassin database in Dovecot

Here is a detailed article on using SpamAssassin (via MailScanner) together with Dovecot, focusing on classifying spam, moving it to the Spam folder in Dovecot, and training SpamAssassin.

Using SpamAssassin with Dovecot

SpamAssassin is a popular open-source email filtering tool that uses a variety of heuristics to classify emails as spam or not spam. Dovecot, on the other hand, is an open-source IMAP and POP3 server for email delivery. When used together, they can provide a powerful solution for managing email spam.

Setting Up SpamAssassin with MailScanner

The first step is to install and configure SpamAssassin using MailScanner. MailScanner is a comprehensive email virus scanner, spam filter, and wrapper for other email programs. It is designed to work seamlessly with SpamAssassin.

# Install MailScanner
sudo apt-get install mailscanner

# Configure MailScanner to use SpamAssassin
/etc/mailscanner/runmailscanner.pl --configure

During the configuration process, you will be asked to enable SpamAssassin. Select "Yes" when prompted.

Configuring Dovecot

Next, you need to configure Dovecot to move spam emails to the Spam folder. This is done by adding the following lines to the Dovecot configuration file (usually located at /etc/dovecot/dovecot.conf).

# Enable SpamAssassin support
mail_plugins = spamassassin

# Set the spam_score threshold
mail_spam_score = 5.0

# Set the spam_mailbox
mail_spam_mailbox = Maildir/Spam

Restart Dovecot after making these changes.

sudo systemctl restart dovecot

Training SpamAssassin

SpamAssassin can be trained to improve its ability to correctly classify spam. This is done by marking emails as spam or not spam in your email client. For example, in Thunderbird, you can do this by right-clicking an email and selecting "Mark as Junk" or "Not Junk".

Summary

• Install and configure SpamAssassin using MailScanner.
• Configure Dovecot to move spam emails to the Spam folder.
• Train SpamAssassin by marking emails as spam or not spam in your email client.

References

• MailScanner: https://www.mailscanner.info/
• Dovecot: https://dovecot.org/
• SpamAssassin: https://spamassassin.apache.org/
• Thunderbird: https://www.thunderbird.net/