Outgoing mail server gone under El Capitan

Iantindal wrote:

My solution, with the help of Apple, involved - Mail > preferences > Accounts tab > click on outgoing server dropdown > Edit SMTP server list > advanced tab > authentication had reverted to 'none' I set it to 'password' then entered my apple ID details and my unsent mail started sending before I saved the setting.

Thanks Iantindal!

After much frustration (probably because I was looking for a solution for my non-iCloud email accounts) this totally worked. Indeed, the authentication had reverted to 'none' for my gmail as well as for my other, 'internet provider' email account. I reset authentication to 'password', entered the password associated with the account, and presto!, the accounts were sending emails again.

One extra note: I had some additional frustration because I forgot about Google's 'application specific' passwords. I had to generate a new one through my Google account, and cut and paste it into the password box for BOTH incoming and outgoing mail servers for my Gmail account.

The new update to El Capitan, 10.11.1, supposedly has solved this problem. Mine was already working after a very tough initial week with El Capitan, and I'm happy to say that it still is after installing 10.11.1. So I'd suggest that anyone who is still struggling with this problem first install 10.11.1 from About This Mac>Software Update under the Apple Menu, or from the Mac App Store.

Lordy. Thank you. Wuz going nuts.

Thank you Drastic Bunny!

Despite 10.11.1, things are not going a 100% yet. This morning when I woke up my MacBook Pro and tried to check my mail, Mail was 'checking mail...,' and in a dimmed message below it indicated '23 new messages.' But nothing happened. It just got stuck in that mode, and no downloading occurred. I did a cold re-boot that did not help. Only after I disabled, then enabled again the mail setting in System Preferences/iCloud did the messages get downloaded...

Sounds like progress to me. The problem we all had before 10.11.1 was with sending mail. Sounds like in your case, sending mail may be OK but they screwed up the incoming mail! I do see where they've just sent out beta versions for testing of a 10.11.2 . . .

I've given up trying to get it to work. Downloaded Outlook 2016. Sends and receives fine. If they get it working I'll move back but not holding my breath.

Actually I had the sending email problem as well. 10.11 with me would neither send nor receive email, so yes, 10.11.1 is progress...

Outgoing mail server has returned! Thank you!

Ding! OR_CD's solution works perfectly, thanks!!

I went to Mail Preferences in the Mail app on my MacBook Pro (2009 El Capitan) and found that my outgoing server was renamed to "Me" in my SMTP server list. I went into the dropdown and clicked "Edit"... I then clicked on "Me" in the list, then down below went to the "Advanced" tab... I noticed it was "Apple Token" and my old, old, old, me.com email address with no password. So I changed the dropdown to "Password" and entered my current me.com email and my password. I then unchecked "auto update" - once apple has fixed this glitch, I will recheck that box. I then clicked "OK" and closed out of Mail Preferences and clicked "Save"... it then sent the mail sitting in my outbox! YAY!!!

( I've not read all messages above but when I used the right mouse button on a mailbox at the left side in the mail program and choose the option change "mailbox name" suddenly all was "back in business", hopefully someone else can use this info )

Do you have a three-button mouse or did you Command-click on something?

I used an Apple mouse

Note: in my mouse settings I've checked the second option "Secundair klikken" (this is Dutch) under the second tab "Meer bewegingen" (this is also Dutch;-)

Wow, I have had immense problems with my MacBook air since Yosemite and El Capitan - super slow, virtually a dead machine. The today mail dumped my outbound server details so I came across this thread. Which did not help my mail issue - I had to rebuild all the details again on several accounts. However, after having read the problems I decided to turn ICloud mail settings off and leave them off and my whole computer is working like it did two years ago... flippin annoyed about the problems I have been experiencing... perhaps windows is now a better option.