Mail Queue

[TooLittleTime]

I recently had a mailing to a number of recipients.
After sending, what I received in my mailbox told me which emails failed and for what reasons.
However, when I checked in WHM, went to the Email section, and went to Mail Queue Manager, I saw a number of emails still in the Queue.
Could someone tell me in detail,
Why they are there?
How do these compare to those that I already discovered in my inbox as returned due to failure-to-send reasons (recipient no longer exists, box full, etc.)?
Have they been sent or not? Or, were they sent, and rejected?
How do I get them sent? (I already tried using the "Attempt to Deliver all messages in Queue " link, but only some of them went.)

I have scoured this website looking for docs or manuals that cover this issue, but with no luck.

Could use ALL the input anyone can provice, so as to learn from the experience.

Thanks in advance.

[chirpy]

All the information regarding email delivery is in /var/log/exim_mainlog (linux). If you're looking for documentation, then you would have to research over at http://www.exim.org as that is the MTA used. For specific issues, you should try searching these forums and/or the exim mailing list from the exim.org site.