We will create a new multimap to selectively block specific senders using the mail envelope. Our rule will filter based on the right hand side only – matching the domain part of the envelope email:domain. In addition we will use the prefilter attribute with action = “reject”; to avoid subsequent costly tests – reject will […]

We will allow users to categorize mail as Spam by placing them in user-specific Spam mailboxes. Contrary moving a message flagged as Spam to any other mailbox will relearn it as Ham. IMAPSieve configuration Dovecot supports this via its IMAPSieve plugin which we will configure in our custom configuration /etc/dovecot/local.conf to avoid touching release-specific files in […]

Rspamd is able to use combinations of words to qualify messages as Spam or Ham. We will configure it to learn these tokens per user and store them in redis with a TTL of 100 days as spammers may develop new methods over time. The key idea of OSB algorithm is to use not merely […]