I have explored the forums for a solution to this problem. Most who experience this problem can trace the source to the rules function of Outlook. I cannot, since I have no rules defined in my setup, which follows.
Our mail (POP3) is served through a RAQ3 box hosting two “virtual” mail servers. One mail server is for our primary domain, and another hosts a secondary domain. Any mail to the secondary domain is forwarded to it’s corresponding account on the primary mail server. We also have a Barracuda 300 Spam Appliance, which all mail goes through before reaching the mail servers.
Mail is retrieved by my users using the Outlook 2000 mail client. It is setup not to syncronize or download from the secondary account (as again, all that mail is forwarded to the primary mail account), and that secondary account is set not to leave messages on the server.
For the past several weeks, users who have accounts on the secondary mail server receive triplicate messages from that account only. Messages addressed to the primary email address are not affected, and users receive one-each of these messages. However, messages addressed to the secondary account come in once, then one hour later come in again (if not retreived before that time), and finally once again one hour later.
I can see through the Barracuda’s message log that the duplication is not happening prior to reaching the spam filter. Examining the headers in the duplicate emails find no difference in them except in the “X-UIDL” line at the very end of the header information. Often this line is very long, with the same character string except for the last few characters. This info seems to be added by the Barracuda. Note the example:
Content-Transfer-Encoding: 8bit
Message-ID:
X-Virus-Scanned: by Barracuda Spam Firewall at xxxxxxxxxxx.com
X-Barracuda-Spam-Score: 0.00
X-Barracuda-Spam-Status: No, SCORE=0.00 using global scores of TAG_LEVEL=2.0 QUARANTINE_LEVEL=2.0 KILL_LEVEL=6.5
X-UIDL: =0C!!J(!”!DC5″!G/p”!
Keep in mind that while ALL mail goes through the Barracuda, and thus, all mail gets this header info added, only the secondary accounts get the mail triplicated, never the primary.
I’ve tried deleting and recreating the accounts, as well as the secondary mail server itself. I tried eliminating the forward from secondary to primary, and setup Outlook to access each server to retrieve mail, to no effect. I even disabled our network’s Symantec Anti-virus email add-on, to no effect.
I desperatly seek a solution to this problem.