Plesk for Windows 8.6, MailEnable Standard and SpamAssassin

[MicheleZ]

Hi guys,
I'm unable to get SpamAssassin working on a default configuration of the software listed in the subject.

On plesk all AntiSpam settings are configured correctly.
If I send a spam test message to a mailbox hosted on this machine, SpamAssassin seems to ignore it and that mail reaches the user's Inbox without any problem.

The test message I'm sending is: http://spamassassin.apache.org/gtube/

In ME MTA logs I see:

03/16/10 13:45:18 Processing file 47957CBC4E9F4C6E9E3C5B81DA946CD1.MAI from queue SMTP
03/16/10 13:45:18 MTADeliverMessage::Executing external COM event pleskmemta.PleskMEMTA with message 47957CBC4E9F4C6E9E3C5B81DA946CD1.MAI from SMTP queue
03/16/10 13:45:18 ME-MTA-ROUTE [47957CBC4E9F4C6E9E3C5B81DA946CD1.MAI] from [SMTP] Connector queued to [SF] Connector as [598FEF877C994CF791553DF87969C2A9.MAI]

In SF logs:

03/16/10 13:45:38 [598FEF877C994CF791553DF87969C2A9.MAI] Mailbox (info) on postoffice (domain.com) executed a delivery event (D:\Program Files\Parallels\Plesk\admin\bin\memailfilter_usr.exe domain.com info 598FEF877C994CF791553DF87969C2A9.MAI).
03/16/10 13:45:38 [598FEF877C994CF791553DF87969C2A9.MAI] Delivered message from [SMTP:sender@gmail.com] to PO=domain.com MBX=info FLD=\Inbox

What's happening?