Forwarding mail to an out of quota account produces a loop

[cmargena]

Hi Everybody,
I have the following problem:
Suppose there is a mail system (based on Zimbra) with a user that set up a filter to forward all mails to an external account. When mail arrives to Zimbra it is correctly forwarded to the external mail system, but suppose that the external mail account is out of quota.
What happens is that the external mail system produces a reply warning Zimbra that the receiving account is out of quota to Zimbra but (as I could see) it removes X-Zimbra-Forwarded header as it produces a new mail, so when that mail is received by Zimbra it is forwarded again to the external account starting in this way an infinite loop.
My question is: Is there any way to avoid forwarding out-of-quota emails or it is a user responsibility to filter them?

[cmargena]

Originally Posted by cmargena

Hi Everybody,
I have the following problem:
Suppose there is a mail system (based on Zimbra) with a user that set up a filter to forward all mails to an external account. When mail arrives to Zimbra it is correctly forwarded to the external mail system, but suppose that the external mail account is out of quota.
What happens is that the external mail system produces a reply warning Zimbra that the receiving account is out of quota to Zimbra but (as I could see) it removes X-Zimbra-Forwarded header as it produces a new mail, so when that mail is received by Zimbra it is forwarded again to the external account starting in this way an infinite loop.
My question is: Is there any way to avoid forwarding out-of-quota emails or it is a user responsibility to filter them?

More on this: The problem is that Zimbra does not have any "standard" rule to avoid forwarding mails from for example: "POSTMASTER" or "MAILER-DAEMON"

[John Siu]

Add a filter rule for "POSTMASTER" | "MAILER-DAEMON" above forwarding filter, and check mark [Do not process additional filters] in its setting.

[cmargena]

Originally Posted by John Siu

Add a filter rule for "POSTMASTER" | "MAILER-DAEMON" above forwarding filter, and check mark [Do not process additional filters] in its setting.

This has to be done user by user or can be done automatically?, Like having a master rule.

[John Siu]

If the forwarding is configure at the admin gui, then I have no idea for now.

[ewilen]

You may be able to create a script which will step through all your accounts and add the necessary filter rule, but AFAIK there's no built-in method of creating a master rule.

This might be a good suggestion for an RFE--either the ability to create master rules, or an option to suppress certain types of filter actions on mail that matches certain profiles.

[cmargena]

Originally Posted by ewilen

You may be able to create a script which will step through all your accounts and add the necessary filter rule, but AFAIK there's no built-in method of creating a master rule.

This might be a good suggestion for an RFE--either the ability to create master rules, or an option to suppress certain types of filter actions on mail that matches certain profiles.

Ewilen,
1. What is the way to create an RFE?

2. Is there anyway to tweak sieve in order to have this rule attach to every user that has a filter? (I do not know in detail this tool but I think this is the way to have this working)

[ewilen]

Originally Posted by cmargena

Ewilen,
1. What is the way to create an RFE?

Visit Bugzilla Main Page - Zimbra, create an account if necessary, open a bug and mark it as "enhancement" for severity. I also generally prepend "RFE:" in the subject to help identify the purpose of the report.

2. Is there anyway to tweak sieve in order to have this rule attach to every user that has a filter? (I do not know in detail this tool but I think this is the way to have this working)

I don't know the details of sieve or how it's used by Zimbra to give an answer. I assume it's possible, although the implementation might not be in sieve per se, but in the Zimbra subsystem that creates the sieve filters.

[cmargena]

Originally Posted by ewilen

Visit Bugzilla Main Page - Zimbra, create an account if necessary, open a bug and mark it as "enhancement" for severity. I also generally prepend "RFE:" in the subject to help identify the purpose of the report.

I don't know the details of sieve or how it's used by Zimbra to give an answer. I assume it's possible, although the implementation might not be in sieve per se, but in the Zimbra subsystem that creates the sieve filters.

Anyone from development that could add on this last one?, I can write what it takes and give it to you.

[brumdo]

I don't think that you would want to do block all messages from POSTMASTER or MAILER-DAEMON. People need to know that their mail is bouncing, but I agree that this is particular example is a problem.

We have a similar issue happening and what we've done so far is tell the user to stop forwarding their mail to the external address and then block that external account on our spam filter appliances.

Sorry I don't have any solution to add.