can't send mail using exchange account in mavericks

By taking the following actions, I FINALLY got Mail to work for me:

1. Change Description to <domain>/<username>

2. Check the box to store draft messages on the server

3. Quit Mail and restart

I had to do BOTH 1 and 2 above to get it to work. It has been sucessful so far *(tested with a few different attachments that used to give me trouble). I will keep monitoring to see if anything changes in different work settings...

This seems to be enough for me to get it work:

2. Check the box to store draft messages on the server

Sorry to poor cold water on this one. I have had the 'store draft messages box' ticked and no change at all. I still don;t get why this is a problem and hasn;t been subject to some sort of input/upgrade from Apple. It looks to me like I will have to dump Mail which is a complete pain in the ***.

ag174,

for 1, did you do <domain>/<username> or <domain>\<username>?

I did <domain>\<username> and it worked better for me but after a couple of days I had the issue again. Odd though, it was not as bad as it was previously.

I just tried the #2 suggestion "Check the box to store draft messages on the server". I have no idea why this would make a difference but it does seem to work better for me.

it should be a backslash so \

<domain>\<username>

@malcolm - I as well already had it checked. It seems it is with just attachements.

Same problem here. Anythign with a message attached is bad news. I have four email accounts: ICloud, an exdhange account and two POPs.

I originally had this aggravating problem but after changing a few of the recommended fixes I soon went back to what I had originally, then loaded Software OS X 10.9.2 (13C64). I don't have any problems with either my iMac or MacBook Pro. Both are using the latest Mavericks update. Sometime back I changed my email settings to all using IMAP. I use iCloud for contacts and calandar and "Find My Mac" only. Whatever happened I am happy to have excellent service with email again (heavy professional user).

Let me repeat what solved my problem: no funky domain name, no IMAP, no nothing, just

check the box in the "Mailbox Behaviors" => Draft: Store draft messages on the server

So I've had the exchange account issue for awhile for 5 different exchange account emails. I recently had to re-install Mavericks and the issue litterally stopped immediately.

Purely speculation, but could this have been a glitch with the upgrade version of the software? Because after a clean install it has gone away.

I don't know enough about computers to even begin trying what some of you have suggested. Where do I go to find "Change Description to <domain>\username and "check box to store draft messages on server". I went to system preferences but did not find those options. I am so frustrated that I can't send a simple E-Mail with 3 pictures attached. I clicked the send icon (paper airplane) but did not hear the sound that usually goes with it. I checked my SENT and nothing was there to indicate it was gone. As I write this (2hours later), I suddenly hear the SENT sound and a message in the corner saying Mail Delivery failure. What is going on??

What worked for me:
Mail > Preferences > Accounts, then on the exchange account, under Account Information tab I changed/edited the "Email Address" by entering my name & email address for that account.
(Nov. 2016)