My own mail server of course, accessible through IMAP, a stand-alone web mail client (Roundcube) and the mail app buily into Nextcloud. The server supports Siev

My own mail server of course, accessible through IMAP, a stand-alone web mail client (Roundcube) and the mail app buily into Nextcloud. The server supports Sieve filtering (which, for those who use Nextcloud or Owncloud, currently interferes with the mail app necessitating a patch to get it to work). Spam is filtered (through Spamassassin and greylistd) and moved to a separate folder (through Sieve). Any spam which made it through can be moved manually to a spam folder from where it will be used to train the filter through a cron job which runs nightly.