mail stuck in outbox, general mail problems

I have this same problem, with Yosemite (OS X 10.10.1).

First, Mail has been awful for over a year on this computer -- it's very slow, and always crashing ("not responding").

Now, I can't send any emails, although I can receive emails just fine.

Any "sent" email sits in my Outbox forever. It never sends. I can't delete it from the Outbox (it's permanently stuck there), nor can I move it into the Draft Folder.

I spent an hour on the phone with Comcast, thinking I had a blocked Port, and we went through a lot of solutions which did not solve the problem.

Comcast told me to contact Apple but my Apple Care Plan expired months ago.

This is what I tried:

Deleting and re-entering the email accounts (comcast.net and gmail.com). This did not work.

I tried Rebuild, which did not work.

I've tried a few of the suggestions here, which did not work.

Three other things are going on too, that might be related:

My Force Quit is buggy. Whenever I try to Force Quit an application, the name of the application remains in the Force Quit window, as if I never told it to force quit.

Many of the Apps (iCal, iMail) on my computer have been really slow.

Our Wi-Fi wireless router signal keeps disconnecting.

Could all this be related to the buggy iMail?

Please help! Thank you!

I am having a very similar problem. It is also eating up all of my memory. My iMac us practically useless now.

Just to say thanks. This worked a treat. I actually copied my Outbox emails into Gmail online and sent them, deleted them and then I didn't need to do the two stage opening and closing of iMail. Thanks for the simple instructions.

Thank you! vaheasalnyan helped me. I unchecked the enable this account and then rechecked it and my mail started going out. Thanks!

I am quite surprised this problem still exists in Mail 9.0 under OS X 10.11.

At some point Apple needs to seriously address this issue with outgoing mails getting stuck, especially if they include attachments. These stucked mails don't only just get stuck, they also block the entire online connection on the Mac. Even Skype goes offline with these stucked mails.

I installed Little Snitch to see the current data traffic in the menu bar or in the Little Snitch Network Monitor - the Little Snitch Network Filter itself is turned off to make sure Little Snitch is not causing the mails to stuck. It's interesting to see that the stucked mails block the online connection for other applications while Little Snitch shows only very small amount of kB/s being transferred - you can also see this in the Activity Monitor app.

How can Mail eat up all online traffic with these stucked mails if there is actually almost no traffic? I close Mail and my other online connections operate normal again. I open Mail with its stucked mails in the pipe and all other apps go offline again while only a few kB/s are being up- and downloaded. This is 100% reproducible.

I understand that it would take a while to transfer attachments of a few megs when Sent Messages and Draft Messages need to get stored on the server (this is a setting in the account settings). In this case I should see high upload traffic in Activity Monitor or Little Snitch and as we know high upload traffic would affect other online activities such as surfing or even Skype. But why do other online connections get affected with only a few kB/s of traffic from stucked mails? Why does Mail block the entire online connection?

Use Gmail - nothing gets stuck there, and it's a free service, unlike Apple $$ hungry.

Turn off cellular data for mail. Wifi too. Then turn off phone. Turn on. Go to mail. It'll have red exclamation in email stuck in outbox. Edit and swipe to delete The message that is stuck. It should finally delete.

TUrn cellular and wifi back on.

THis his worked for me.