Solution: Messages to local addresses are declined

[dirty@]

If you don't have unlimited drweb license installed but use default 15 maiboxes trial license that comes with Plesk and you enable drweb for more that 15 accounts in plesk, then messages to such addresses may be declined with 554 mail server permanently rejected message error

the reason is that now drweb config is set to drop messages to addresses which cannot be checked due to the license limitation

you need to edit /etc/drweb/drweb_qmail.conf and modify LicenseLimit value there from reject to pass:

LicenseLimit = pass

or buy unlimited drweb license..