The SMTP and IMAP servers have been installed and configured, so mail can be sent and received. However, a modern mail setup is not complete without the possibility to filter mails and without anti-spam measures.
Sieve
Sieve is a scripting language for filtering incoming emails. This filtering is done on the server; when using IMAP, filtering on the client is rather useless, since the original messages remain on the server.
Sieve is an extension of the LDA that allows, for example, to move mails to certain folders based ...
