Just went back and forth with support.
This what they said and had me try
Hi,
could you try this workaround, please:
C:\Documents and Settings\All Users\Application Data\Alwil Software\Avast5
avast5.ini
create anywhere section [MailScanner]
and under this section
(add) key "UseAlternateRtfSyncing=1"
I tried what was suggested to no avail.
I am still getting the question marks.
I informed them and this was the reply.
Hi,
Unfortunately we have no more solution for you then turn off the clean-messages.
Best regards,
ALWIL Software a.s. support team