Re: [exim] Newbie question on queues

> Just starting out on Exim and a bit confused as to the purpose of queues.

I am new to Exim as well, but not new to e-mail delivery in general.
The purpose of the delivery queue is a temporary holding tank for
messages waiting to be delivered. This could be because mail is
coming into the server faster than it can be delivered to the final
destinations, or because a remote server is reporting a temporary
failure of some kind. It is true that a "temporary" failure may be
persistent and still exist later when the queue runners execute, but
in many cases those temporary problems will clear up and the mail can
be delivered through later. This can be because of legitimate
temporary failures such as a server being out of disk space, or could
be imposed by policy (such as greylisting, for example). It is up to
each server operator to determine how long they will keep re-trying
delivery, and how often, depending on the type of mail you're
delivering through (importance, urgency, timeliness of the content,
etc.). Some will continue to retry delivery for weeks while others
will see no need to retry at all and discard anything that can't be
delivered immediately.


-Justin