Because of a change in cPanel's implementation of exim due to a
security issue, it is no longer possible to completely bypass
MailScanner for outgoing mail.
However, by default MailScanner will not scan outgoing mail for spam.
In general there are only two reasons MailScanner would be marking
outgoing mail as spam:
1. The setting for WHM > ConfigServer MailScanner FE >
MailScanner Front-End > Advanced Settings > Spam Scanning is set
to "FromOrTo:" instead of the default "To:". The solution is to set this
back to "To:".
2. The mail is considered to be incoming mail because there are
multiple recipients and one or more of the recipients is hosted on the
server that is running MailScanner.
If the reason is number 2, there are a few potential solutions:
a) The sender can remove any accounts on the server from the recipient list for the email.
b) Fix the problems with the actual email that are causing the mail
to be marked as spam. Look at the spam report to find out what
spamassassin tests the email is triggering. Then you can either change
the scores for the tests that are triggering on these emails, as
described in our FAQ
here
(which may reduce spamassassin's overall effectiveness), or get the
sender to construct the mail differently or send it in a different way
that doesn't trigger these tests. You should be able to find out more
about each of the spamassassin tests by searching google. (There is also
information about most of the tests
here.) You could also try training the bayes database to teach it that this isn't spam (see
this FAQ), but that probably won't be enough.
c) Whitelist the sending email address. This will open the server to
spoofed email spam, but it may be the best option and your users will
just have to live with the extra spam they will receive due to this. If
it is a mailing list with multiple recipients, you should be sure to
check the setting for "Ignore Spam Whitelist If Recipients Exceed" in
the MailScanner Configuration and make sure that this is higher than the
number of recipients on the mailing list, or get the sender to reduce
the number of recipients for each copy of the mail.
