I have two Accounts set up in Mail.app. One business, one personal via AOL. Comcast is my ISP. Attachments are limited to around 10-20 MB.
I tried to send an attached 5 MB Folder that I thought contained five 1 MB video clips. When that didn't work, I split the contents into 5 separate e-mails. When that didn't work, I noticed that these were all the actual sizes were GB not MB so I knew they were way too big to go as attachments. However, Mail kept trying to send them. Now, the personal account just spins but occasionally, new, outgoing mail will work.
Based on suggestions in this Forum, here is what I have done for troubleshooting so far:
Deleted the messages from the Outbox
Deleted the messages from the Drafts mailbox
In Mail Preferences, I deselected "Store Drafts on the Server." (My guess was not only was Mail trying to send the messages, it was also trying to store a draft of each message.)
I forced quit Mail and went to ~/Library/Mail and deleted any copies of either the Message or the Attachment that I could find including those in the Outbox, Saved, and Recovered mailboxes/folders. (I sorted the various folders by size making it fairly easy to find these large attachments and found the individual messages by the created date.)
I can retrieve my AOL Mail by going to their website but I still cannot get my AOL Account to work in Mail.app.
What do I do next? Should I just delete the Account and recreate it? Can I do this without losing old saved messages? Note, everything is backed up by Time Machine.