Q: can't send mail using exchange account in mavericks

I started having the same problem.. surprisingly after today's update to Mail and iBooks apps.  Mail won't send (it will sit in the "On My Mac" outbox for a couple of hours) and then I get a notification to "Try again with a different server".  It seems that plaintext messages get sent perfectly.. but even if I attach a 250kB file, the message will not send, no matter what I do.  Very frustrating.

I have the same problem. Even after installing the Mail update for Mavericks. Are there any other threads around to address this issue or have any workaround? At least I see others have the same issue which makes me think it is not an isolated issue.

Figure I will add my comments in here as well. Same type of issues as above. Using o365 exchange, after latest mail app update, now all exchange email with attachments seem to just sit my outbox.

If there is not attachment (or a meeting request invite), it seems to work more often than not. but I can't get into bug testing that deep. Attachments though, those always cause an issue.

Exactly the same problem.... mails sit for minutes until the "select outgoing server" windows comes up. Then, after selecting the same server the mail is sent.

It is driving me crazy!! Any news on the solution?

Thanks

I also have this problem.  Latest mail update, exchange emails with attachments sit in my outbox and will not send.  This does not happen in Outlook, only in Apple Mail for Mavericks.  This is still happening after installing the Mail Update for Mavericks.

For me, even when the email comes back to select the server again, trying to send again with Exchange will fail on successive attempts.

Has anyone seen any responses on this issue?

My only choice is to use OWA to send an email with an attachment.

I also have this problem. Mails with attachment are (sometimes, not always) not send. After a few minutes, "select outgoing server" is shown and the mail is send. If I open the actiivity window in Mail Cmd Option 0, then is shows "Adding mail" (I do not know the exact message since I have a dutch version). But this never ends. It also helps to stop this process (hit the stop sign). Then stop and start mail and the message is send immediately.

I hope somebody finds a solution. at the moment Mail is useless since it sometimes does not send mail, which is a rather import feature of a mail programm 

I've had the exact same problem as everyone else... One thing that seemed to work was "unchecking" Use Autodiscover Service in the email account set up area.  Simple fix, but worth a shot...

I have unchecked the Autodiscover Service, but that has not helped. I still have the same problem. As said most of the time with emails with attachments are not send, but today I also noticed that a mail without an attachment had not been send.

I'm just adding myself to the list - exactly the same problem of sending emails, especially with attachments - 'select outgoing server' window comes up most times. Today an email with two pdf attachments sent on the second attempt but the attachments were empty files. When sending screenshots to my IT support service the screenshots were stripped from the email.

Also, whilst writing emails I twice received a message that said 'some actions taken while the account exchange was offline could not be completed online' - followed by a longer message. Net result was that the message I was working on was found in my recovered messages folder - but the window stayed open. I've never seen this before today - using same account on the same netork connection.

I hope we'll see a fix soon.

I have the same problem too.

Even small, 50Kb attachments come back with the error message from the exchange server.

They usually go out after pretending to edit it, and trying to send it again the second time.

Mine is a Macbook Air with mavericks.

My colleague with a Macbook Pro and with mavericks does not have any problem sending attachments.

I also do not have problem sending attachents through gmail account.

Also my mail searches cannot find some of the emails.

Very frustrating.

One problem after the other (Wifi, Mail reindexing, Mail searches, attachments).

Same here ... can send email with mac mail using an exchange account when the email has nothing attached, but when I attach something that is modest in size (0.5MB), i get the same behavior - stuck in outbox, eventual error message saying can't send w selected server ... really painful

Same problem here, after all recent updates. Seems to be something that Apple needs to fix.

Hi all,

With the internal server, external server, user name and password all defined, I disabled both 'use auto discover service' and 'use only this server'. When I open a new mail it gives me a choice though the correct exchange server is always the default - I am running two exchange services and two POP accounts, plus gmail.

Since then, I have had no problems sending although it still seems slower than I remember - and receiving is still much slower than my iPhone or iPad.

I hope that helps some of you.

Cheers