We have been using ISPConfig servers for a long period and host many websites. recently clients are complaining about lot of spam emails in there inbox and want to move to gmail or microsoft mail service. Any better solution? we have spamassasin, amavis installed as per centos installation manual of ispconfig.
There are many things that you can do to improve spam protection. 1) use RBL's or add some more RBL's, see System > server config > mail. 2) Lower the spam score in the policies that you use under Email > spamfilter policies, check mail headers of non detected spam to see which score they got. 3) Update sapmassassin rules with sa-update command and restart amavis afterwards. 4) Add additional spamassassin rules: https://schaal-it.com/current-rules-spamassassin-schaal/
