Mail SMTP (outgoing) does not work after Yosemite upgrade

This worked for me! Thanks for the detailed instructions.

I've just done a complete fresh install of Yosemite on my Mac and skipped the AppleID setup. First thing I did was set up the mail account that was giving me grief before and it still doesn't work !!!!

What is going on Apple?

I'm having the same problem with the Outgoing Mail Server, tried all of the above but none seems to work !

I'm not sure this way suitable for yours or not, but I do.

It is worth to try following instructions that I found in another forum.

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I found another forum post on here regarding the same issues with IMAP, and the solution was to uncheck the option under mail preferences -> accounts -> advanced -> and UNCHECK "automatically detect and maintain account settings". I unchecked for all accounts, closed and reopened mail, and every email that has come in to these accounts since I installed Yosemite finally all downloaded. Hope it works for others as well.

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by Symtex

http://www.dslreports.com/forum/r29613112-BC-IMAP-with-Mac-OS-10.10-Yosemite

That worked ! Thank you Sir !

Try 465 SMPT port ...

It's good for me !

The solution:

Close Mail

Go and edit /Users/youruser/Library/MailData/accounts.plist

(It's a hidden folder. To show --> defaults write com.apple.finder AppleShowAllFiles -boolean true ; killall Finder)

DeliveryAccounts:

Change UserAllowsInsecureAuthentication --> <false/> TO <true/>

It's done!

It seems to be the solution. But for me, im not a programmer, its very difficult to understand how to do it.

😟

I owe you a drink. This has sorted it for me.

Once you find the .plist file double click to open it in TextEdit.

Quit mail

Open up Finder

In the Finder menu bar select Go > Go to folder

type in ~/Library and click Go (on my kb the "~" is next to the left shift key)

Open the folder Mail

Open the folder V2

Open the folder MailData

Double click to open Accounts.plist (should open in TextEdit)

Find the block of data that contains the offending mail account

Find the line within this block that says <key>UserAllowsInsecureAuthentication</key>

Change the line below this from <false/> to <true/>

Quit TextEdit

Restart mail

You are the Master! That's the solution.

And you too... Im very grateful master. Its working!

@HelicopterJon

This worked, can't believe it ! If I could buy you a beer I would.

It worked! Thx.

"I found another forum post on here regarding the same issues with IMAP, and the solution was to uncheck the option under mail preferences -> accounts -> advanced -> and UNCHECK "automatically detect and maintain account settings". I unchecked for all accounts, closed and reopened mail, and every email that has come in to these accounts since I installed Yosemite finally all downloaded. Hope it works for others as well."

I hadn't see your suggestion until after I had tried it as well, but I also (randomly) unchecked "automatically detect and maintain account settings" just to see what it would do, and my mail began sending immediately. I didn't even have to restart the mail client. I didn't change anything else. Just unchecked that box and everything started working. (note--I'm using the default mac email client) . Also, the box rechecked itself on its own and everything is still functioning fine. Hope this works for others.