Outgoing e-mails with large attachments getting deferred

[dsirrine]

I have a problem with e-mails containing more than 20M of attachments getting stuck in the deferred queue. They will bounce from active to deferred back to active until about 5 or 7 days go by an they will be dropped completely. My web mail MTA timeout is 600 seconds and in our current global settings, our maximum message size is 819200kb (100MB) yet some of the e-mails that are larger than, say, 20M are still getting deferred. Not sure why.

[phoenix]

Originally Posted by dsirrine

...our maximum message size is 819200kb (100MB) yet some of the e-mails that are larger than, say, 20M are still getting deferred.

I think you'll find that your figure of 819,200kb (I'm assuming you mean KiloBytes here so correct me if I'm wrong) is actually 800MB. Where are you getting that figure from?

[dsirrine]

I assume, that the lower-case "b" is indicating bits and not uper-case "B" for Bytes. If I'm wrong in my assumption, please let me know. Regardless of the symantics of what the application is looking for as the maximum size of a message, the 819200kb should be more than sufficient to allow a 20M e-mail to go through. Also, if it is, in fact, due to size. Why am I not getting an NDR for "message too big"?

[ewilen]

Are you sure this isn't an issue at the receiver end? I've seen mail to Yahoo getting deferred which contains large-ish but not huge attachments. Sometimes it eventually gets through, sometimes it's returned to the sender. I posted in a thread about this recently. At first it looked like it might be unique to Zimbra->Yahoo connections, but now I think that Yahoo is just throttling large attachments if they keep coming from the same source.