On smarthost.eu servers there is a multi-stage anti-spam protection installed.
-every e-mail is checked by the SpamAssassin program and messages that have a score above 20 points (according to the SpamAssassin specification - a value of 20 means practically 100% certainty that it is spam) are automatically rejected.
-each e-mail is checked on several black lists of RBL (Realtime Black List) including: bl.spamcop.net, cbl.abuseat.org, sbl.spamhaus.org, xbl.spamhaus.org. However, we use our own address exclusions from the above lists.
-we use our own list of spammers, which we block by IP addresses.
-we use sender verification to ensure that the sender's domain exists, etc.
Each user of the server can set the rules for the SpamAssassin program in the panel, which will allow, for example, adding the word *** SPAM *** to the message titles or just to delete spam. Settings can be made for the entire hosting account or for individual email accounts.