What happens to oversize messages if. . .

[dwmtractor]

Two possible issues:

1) I have temporarily increased my message size limit in the admin UI Global Settings/MTA/Maximum Message Size to 15MB in order to import some of my converted users' inboxes, with instructions that they have to clean house soon. I'd like to ratchet that limit back down in order to prevent new oversize messages from coming in. If I do so, does Zimbra care about the now-over-limit messages that are already in the message store, or does it only apply that test to incoming messages?

2) During the conversion phase I also have fetchmail pulling down some users' pop accounts. I presume Zimbra will simply reject messages that are over-limit, but what happens then? Do they stay in some sort of fetchmail limbo, do they /dev/null, or do they bounce somehow? And is there any way for me to monitor or control this?

[phoenix]

It should make no difference to over sized messages if they're already in the store, it's only for sending or uploading new messages.

For the fetchmail messages, they should, IIRC, end up in the deferred queue.

[mmorse]

Also, don't know if you saw this or not -too many old posts to sort through- but just so you're aware:
(Even though your trying to purposely down-size/limit your attachments on that tiny server, others searching this thread may wonder about the opposite direction.)

good to hear - another trick I've found is setting the zimbraMtaMaxMessageSize 10% larger than the zimbraFileUploadMaxSize.

Say both are set to 10MB (and you tell everyone they can send 10MB attachments):
- An 9MB attachment and 100KB message body text. The attachment may be less than the 10MB zimbraFileUploadMaxSize, and so it'll get accepted by the file upload system. But when it's converted into a MIME message it ends up base64-encoded. Then add 100K of regular body text, and the resulting message (say 10.3MB or so) is then handed off to postfix, which checks zimbraMtaMaxMessageSize and promptly rejects the message if it's over the limit of 10MB.

Of course set zimbraMtaMaxMessageSize larger if you want to allow emails with multiple large attachments.

(And of course don't forget the registry key for the import wizards.)
Also, there's a spamassassin setting to not scan/spend cpu resources on really large messages that are over x value in size - adjust accordingly.

[dwmtractor]

For the fetchmail messages, they should, IIRC, end up in the deferred queue.

At which point I look in that queue and will find them; do I have a choice of downloading them somewhere separate, or only deleting them? And does the administrative user (or anybody else) get a notification of the deferral or does it just sit there till I remember to have a look at the queue status?