After a lot of work and Parallels support, i could intall SpamAssassin in Plesk 9.3 and MailEnable 4 Professional. But for 4 days, it is not working (again). I've checked all the steps from Parallels: 1) To enable Plesk mail filter it needs to set value in registry HKEY_LOCAL_MACHINE\SOFTWARE\Mail Enable\Mail Enable\Agents\MTA\Pickup Event Enabled = "1" Then restart MailEnable MTA service. -- 2) Then I checked MailEnable configuration deeper and found out that personal events for mail boxes was disabled. I enabled it using the similar way HKEY_LOCAL_MACHINE\SOFTWARE\Mail Enable\Mail Enable\Connectors\SF\Process Mailbox Events = "1" then restarted Postoffice connector. But nothing occurs... I think there's a problem with MailEnable MTA Connector. When i asked: > Only a question about the MTA event. We had actived the >"Mail Enable\Agents\MTA\Pickup Event" with the "memailfilter_usr.exe". But > we know that there is also "memailfilter.exe". Parallels Support says: Please do not change this configuration. I rolled back the change you made. Because Plesk provides with dynamic module for MailEnable pleskmemta.PleskMEMTA. memailfilter.exe is outdated Plesk mail filter which was used in old Plesk versions. It is not excluded from Plesk package by internal means. memailfilter_usr.exe is the mail filter which is executed on each mail box which has any mail services configured. So, now I have [x] Enable Pick Up Event checked and nothing in the field below. And [ ] Process pickup after filters instead of before, unchecked. And Program to execute on mail file: is empty. (This will create an error because it can be empty, but if you[Cancel] the error, it seems that ME saves the changes). Please, what else can I check?? Thanks a lot!!