Auth smtp/submission mails marked as SPAM by spamassassin

[AllinOneSoftware]

PLESK version 9.5.4, Ubuntu 10.04

I have a plesk server with a lot of clients. Some of these clients use my plesk server as an outgoing mailserver. Because port 25 is blocked by most ISP's they use port 587 for sending emails. Mails that are sent by a client using this mailserver as SMTP server to another domain within plesk gets marked (not blocked) as spam by spamassassin. Mails to external addresses (like gmail) are not marked in any way. Some of the scores the mail gets from Spamassassin are:

- RCVD_IN_PBL (Because all ISP home addresses are in the PBL of spamhaus)
- DOS_OUTLOOK_TO_MX (Because outlook directly connects to this mailserver)
- HELO_LOCALHOST (Because computer/phone identifies itself as localhost)

These emails should not be marked at all because they are sent by an authenticated user. On an old server with a previous version (plesk v 9.2.3, Ubuntu 6.06) this problem dit not occur at all.

It seems that after some searching on the internet that this is related to the version of qmail used by plesk is not RFC 3848 compliant (see http://forum.parallels.com/showthread.php?t=84122). Postfix seems to have a fix (http://adam.shand.net/archives/2008/getting_spamassassin_to_trust_authenticated_smtp_clients/). This doesnt work (http://wiki.apache.org/spamassassin/DynablockIssues) because there is no header that indicates a auth smtp mail. And there are more people with this problem, and no answer that works.

For now i disabled the above scores because this helps, but doesnt solve the problem. Does anyone have a real solution for this?

Thanx in advance

Timon

 

[yNot Creative]

Is there a resolution to this?

We are seeing it, too.

 

[M_N]

We are also seeing lots of DOS_OUTLOOK_TO_MX for internal emails (users on the same server sending emails to each other).

When users on the same server send emails to each other you would expect outlook to connect directly to the MX, it is a false positive.

spamassasin should ignore this flag for authenticated users (and mailenable would need to add a header to indicate the local authenticated user which it doesn't currently do)

 

[M_N]

as a temporary solution I have added these two lines:

score DOS_OE_TO_MX 0
score DOS_OUTLOOK_TO_MX 0

to C:\Program Files (x86)\Parallels\Plesk\Additional\SpamAssassin\etc\mail\spamassassin\local.cf

I'm not sure when the changes would take effect, I just went into the spam filter settings in the plesk panel and clicked OK without changing anything, as I know that immediately causes the changes to take effect.