Keeping this simple; if we have quotas deployed (Dovecot/Maildir) and using LMTP that means that Exim has already accepted the message and is using LMTP transport to hand off for the final stage of the delivery.
Dovecot can be configured to send back a 5xx or 4xx failure if the user is over quota. Lets look at them one at a time... what's the best action? 4xx - Mail would queue and retry on the MX/MTA, probably almost indefinitely, especially for inactive mailboxes. Ultimately these emails would just sit around and eventually an NDR would be generated. Probably not a good idea unless the queue/retry was something short to avoid some temporary disk space shortage. (maybe an hour or two) 5xx - Permanent failure, Exim would have to generate an NDR. I guess in both cases am I correct in that Exim will have to generate NDR's back out to the senders? My concern is with blow back and excessive noise trying to go to spam sources, etc. What are others doing? Would just a really short retry/lifetime to send the NDR be the best course of action? ie: Try to send the NDR X times within a period of time and then just ultimately give up. This way it doesn't clog the queues up with NDR's that are ultimately not going to be delivered... -- inoc.net!rblayzor XMPP: rblayzor.AT.inoc.net PGP: https://pgp.inoc.net/rblayzor/ -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
