Anyone having smtp outgoing mail since Mountain Lion Upgrade?

Changing to port 587 worked for me.

Seen this far too many times now. Last one fixed itself after I daignosed it. I had not actually changed anything after checking it was the usual issue (something else to do at the time) and it just started working. Looking at every time it happens, mail is not attemping to authenticate with the remote smtp server and, in our cases at least, the smtp server rejects the connection because its coming from a blacklisted ip (dynamic ip that should not have an smtp server on it, true of most dsl/cable connections).

Wish apple could find this problem but it does seem to be intermittent.

I am having problems with my iphone5 same problem. I can receive email but can;t seem to send it

Use default ports, ssl

Delete icloud account and rebuild.

Works

Why?

Who knows...

None of the proposed solutions have solved my problem. Hopefully Apple will come up with a definitive solution soon. It's really frustating!

Deleting accounts from Mail and rebuilding them from scratch has worked on several machines for me. Obviously, it can be time-consuming, but has definitely sorted some persistent issues. YMMV.

Does anybody know if it's possible to call Apple and get help with this problem? I have tried every possible thing that others have tried in this forum and nothing is working for me. I've wasted countless hours on this and at this point I'm just getting ticked off. The whole reason for owning Macs is to NOT have to go through this kind of nonsense frustration. I just feel completely stuck and wonder what to do if my Apple care just ran out. Any suggestions?

I upgraded to 10.8.2 at home with no problem awhile ago. Now I am on a trip and none of my mail accounts on my MBP can connect to the server from my hotel room. However, my IOS devices with IOS 6 can connect to the same network using the same mail settings as my MBP. I've tried deleting caches and the usual stuff on my MBP and attempted some of the fixes from this thread but to no avail. I assume my MBP's mail will work when I get home but really wish Apple had a fix. This is silly for email not work.

The 2 step verification was the problem. Since we do not get back the password of 2 step verification for a particular application, you will have to revoke the previous access to the application, create new and then use the same for both incoming (IMAP or POP) and outgoing (SMTP). Have to clear out the fields where we enter regular password and fill in with the new 2 step verification password in the mail app's connection preferences all over.

Now its working for me.

I had problems with sending gmail on the ipod touch and after deleting the icloud account it worked!

I've had the same problem from my Mac Mini and Macbook Pro over the past couple of weeks. It really has dented my opinion of Apple!!!! I'm an IT professional and moved most of my kit and systems from Microsoft. I'm now resorting to using Microsoft Outlook from my Macs as I cant send emails except from my ipad and iphone. Outlook works fine, thoug mac mail still not resolved. I rely on my kit for my living. This is just not good enough.

I was considering a macbook air, not now and looking at the new Windows operating system. This is really poor - definately a bug with my mac software as I can send and receive emails from a windows environment, on the cloud and from Outlook on the mac.

I've tried all the suggested ideas - non work for me. This seems to have been going on for years and still is a problem.

I restored mail from a clone backup made a few days earlier and now all is well. I have no idea what caused the problem or why restoring from a good clone backup fixed everything. I originally restored from TM, but that caused a few of the messages to be garbled such as unkown sender. Apparently it's better to restore from a clone than TM. But I'm 100% OK now.

Here is the information I was given by my server today:

Apple released an update for Mac Mail which closes the connection to the mail server and reports the server as offline.'

He said the problem has been around for several months and that Apple had done nothing to fix the problem so far.

I am still unable to do this either, my server says it is an Apple problem and they are unable to halp and Apple just deny it. I don't understand what a connectin doctor os, or a lot of the helpful hints. Can anyone give me baby steps to rectify this? Apple have no genius reservations for about 5 days and I will be out of the country before this so it feels really urgent thanks for any help

What is a clone backup? Is this something I would have backed up on my exra hard drive? And in which case should I go back to a couple of months ago. I am a bit of a dummy and it sounds complciated but have been unable to send mail for nearly a month and is driving me mad. Thanks