Apostrophe in Address via Barracuda

[Tom Kenney]

I have an odd problem happening. A person is sending us mail, and that person has an apostrophe in her e-mail address. If the message is first routed through our Barracuda, then through the Zimbra OSS box, it never arrives, and the sender gets a 'mailbox is unavailable' NDR. If the message is routed directly to the Zimbra box (bypassing the Barracuda), then it arrives fine.

I tested this by telnet'ing to each (Barracuda, then Zimbra) and using the following message test:

ehlo domain.com
mail from:<sally_o'malley@domain.com>
rcpt to:<tomk@domain.com>
data
subject:Test with apostrophe 5:30
NARF!!!
.
quit


With the above test, the message sent through the Barracuda shows as having been processed by the Barracuda and sent on to the Zimbra box, but produced the NDR. The message sent directly to the Zimbra box went through without a problem.

Is there any known interop problem between Barracuda (or other spam firewalls) and Zimbra? I will say that having an apostrophe in an e-mail address is pretty stupid, but we can't control this because the sender is outside our domain.

[Tom Kenney]

OK, more info, and it gets worse! I tried sending to an address with an apostrophe, and it jammed up the mail queue. That's BAD!!! When trying to view the queue from the admin console, I got 'Server error occurred' message, and the queue would not refresh. I'm rebooting the Zimbra box to see if I can get any stuck messages to flow.

Seems like the apostrophe is behaving like an old-school mail bomb. Anybody else encounter this problem?

[Tom Kenney]

I have now verified that the same issue is happening on the Zimbra NE version, with our paid-for license. I set up a user with an apostrophe in the address, and I can send directly to the Zimbra NE box, but if I route through the Barracuda to the Zimbra NE box, I get the 'mailbox unavailable' message.

I really like Zimbra, but this is a 13'th Hour show-stopper. Is there a work-around for this? An update? We are currently running V7.1.2 on both the OSS box and the NE box.

[phoenix]

Originally Posted by Tom Kenney

I have now verified that the same issue is happening on the Zimbra NE version, with our paid-for license. I set up a user with an apostrophe in the address, and I can send directly to the Zimbra NE box, but if I route through the Barracuda to the Zimbra NE box, I get the 'mailbox unavailable' message.

My first reaction to that comment would be, what (if anything) is the Barracuda doing to the message that gets it rejected by Zimbra? As you can send email directly to the Zimbra server I'd suggest you need to look at the message that's being sent from the Barracuda and also see if there's any further information in the log files.

Originally Posted by Tom Kenney

I really like Zimbra, but this is a 13'th Hour show-stopper. Is there a work-around for this? An update? We are currently running V7.1.2 on both the OSS box and the NE box.

The current version is 7.1.3 but I don't think upgrading will necessarily change this problem. You might want to consider raising a support case for this problem.

[Tom Kenney]

Thanks, Bill. I will see if there's a way I can capture the message as it comes from the Barracuda.

I've been doing more research, and this seems to be a common issue with many mail servers (particularly Linux-based). Some posts I've read suggest it's MySQL behaving more or less properly with regards to the quotes. If I can't get it solved, I will try opening a support case.

Cheers!

[Tom Kenney]

SOLVED!

Turns out it had nothing to do with either Zimbra or Barracuda, but a Watchguard firewall with SMTP proxy enabled for the incoming connection. The SMTP proxy was filtering, and had settings in 3 places for disallowed characters. I disabled the character filter, and messages went through fine!


EDIT: A little more detail for owners of Watchuard XTM devices

We are using a Watchguard XTM 520 firewall. In the SMTP proxy on the Watchguard, there are 3 places where the 'Non-allowed Characters' filter must be either edited or disabled:

1) General->Greeting Rules
2) Address->Mail From
3) Address->Rcpt To

There may be similar settings on other brands of security appliances. I couldn't find any on the Barracuda 300, but it was not blocking for apostrophe, probably because it complies with the RFC for e-mail addresses.