Mail.app: IMAP accounts broken in El Capitan

The problem seems to be widespread across mail servers and clients. Mac Mail, Thunderbird and Outlook are having the same problem. IMAP accounts for some providers do not connect. So far I have the problem with Gmail, Yahoo mail and even Apple's own iCloud. In addition, Mail is now messing up settings and I have to manually reconfigure passwords and server settings and names every time Mail crashes. El Capitan has seriously messed up email productivity. If you can, do not upgrade or return to Yosemite until Apple for once is serious and fixes it's bugs.

After upgraded to El Capitan on my portable 4-year old MacBook Pro, none of my personal domain emails through Hostgator/Dreamhost worked: the passwords for the accounts were not accepted as valid. While I could log in to view emails through their web interface via Safari, MAIL would not work. After spending several hours trying to fix the email accounts with a senior advisor (who seemed quite sharp) and Hostgator rep on chat, we ended up not being able to fix my password problems on all my Hostgator emails for my domains. The Hostgator chat person was unaware of any issue. FYI: Gmail, Yahoo, and Apple Mail accounts did work on both machines after the MBP upgrade to El Capitan. But the business domains' email passwords problem immediately propagated over to my Mac Pro MAIL program, which was NOT upgraded,: MAIL on both machines could not get emails for Hostator accounts.

I resorted to restoring my Time Machine backup until the problem is fixed. That has been going for 14 hours and needs another 5 hours, per the estimate (1TB flash drive). Do not update to El Capitan until this email issue is resolved: most likely it requires updates in software on the part of the providers.

Quick update. The 5-hour estimate ended up being a little less than 2 hours. So 16 hours to restore my 1-TB Flash drive from Time Machine.

The bigger problem is that the email problem did NOT get fixed by using the Time Machine back up using OS Yosemite 10.10.5 just before the upgrade to El Capitan. What to do now?

I was able to fix this issue. In Apple Mail show each individual account's inbox. Right click the inbox & choose edit. Enter the password for the incoming mail server and outgoing mail server. Save. This restored my IMAP email addresses in Apple Mail.

The same thing happened to me too. After the upgrade, although I had specifically NOT enabled other YM or Gmail accounts, the Mail.app decided it was high time it imported ALL accounts. After quickly getting rid of the extra accounts, I discovered that only a fraction of the older emails from my private domain were saved. Enough said, I reverted to Yosemite (since vital software for my work wouldn't work in El Capitan) and I had to manually copy the INBOX database from the last Time Machine backup into the ~Library/Mail folder after enabling hidden files show option. After restarting the Mail.app I had not only full connectivity with older accounts but my emails too. So, this is how I fixed it.

Also, in editing the detail of the account settings as described above, I have found that connections to our Icewarp IMAP server, SSL port 993 now accepts and authenticates properly if only the bare username is used in the username field.

previously I had domain.co.uk\username or domain_controller\username, now I just have the username on its own and it works OK

Tried this approach but the edit has no way of entering the new password. It appears that the developers did not test mail app especially with yahoo and other major mail. This needs to be fixed by Apple ASAP!!

I had a similar problem after upgrading. IMAP accounts were fine, but ALL of my POP accounts were unable to login (with correct user/password). I was able to get it working as follows...

1. Open Mail > Preferences > Accounts

2. Select the account on the left

3. Click the "Advanced" button

4. Un-check "Automatically detect and maintain account settings"

5. Click the "Account Information" button

6. Re-enter the password and close preferences.

7. Right click the account under inbox and choose "Get New Mail from..."

hope this helps

- Dan

Yes. I had to "UNCHECK" "Automatically detect and maintain account settings" for every account. Also my provider had updated ports and secure server addresses that may have helped as well.

My usual mail accounts (Yahoo, Gmail, iCloud) all work ok. In iOS my hotmail account is also ok as is OneDrive.But ElCap Mail

repeats error enter password then fails for hotmail.. Via webmail all is okay. I have, changed password twice, deleted hotmail in sys/accounts and now cannot add hotmail anew.

Extremely frustrating. I have correct hotmail setting printed out but no way to access "advanced settings" - oh and all was good in Yosemite!

Same problem here.

I spent hours of searching and trying to fix it (except downgrade to Yosemite).

The problem seems to be deeper, because I tried Mozilla Thunderbird as a mail client instead of Mail app with same settings, even payed Postbox, but everywhere is some kind of problem to connect to mail server. I tried all the possible ports, mail servers and configurations. From my POV this is the issue of general connectivity, however I'm not a specialist.

Big FAIL for Apple!

I Got Hotmail going in El Cap and iOS 9.1

posted a blog howto at http://suptweetblog.net/2015/11/05/hotmail-mac/

I have upgraded to 10.11.1 and the issue still persists for an account that worked fine on Yosemite. It looks like an issue of the mail client that apple supplies. On the web the account works with the same user ID password

Thank You!

Hi, I am having the same IMAP problem - only with OUTLOOK, I tried Apple mail - it got no where! ... I spent 3 hours on phone to a very nice apple girl... got no where - They told me to ring microsoft, they just wanted money and me to by the latest software and receive a 30day offer of support with it. My very nice Server people have been trying to help - we are getting nowhere.... Can you help I need the info in green. Please

Adding an IMAP Email Account

E-mail address --> MYEMAIL - I know this

Password ---> Password for email account

Username ----> Me

Type —>IMAP

Incoming mail server IMAP server : --> mail.bottle.com.au, Port No. : 143

Check/ Tick <i> </i> —>Override default port

UNCHECK / DO NOT TICK
—>Use SSL to connect (recommended)

Outgoing mail server ( SMTP) ---> smtp.bottle.com.au, Port No. : 587

Check/ Tick <i> </i> —>Override default port

UNCHECK / DO NOT TICK
—>Use SSL to connect (recommended)

Check/ Tick <i> </i> —>Override default port

Add Account
—>Press

NEW WINDOW – Settings for: smpt.bottle.com.au

Authentication —> None, Use incoming server info or user name and password ??????????????

Username ----> Caroline Wareham

Password ---> Password for email account

Unqualified domain —> What goes here???? ??????????????

OK
—>Press

NEW WINDOW – Security

Digital Signing ---> What goes here???? ??????????????

Signing algorithm ---> What goes here???? ??????????????

Check/ Tick - Sign outgoing messages<i> </i> —>Do I tick this???? ??????????????

Check/ Tick <i> - Send digitally signed message as clear text</i> - Send digitally signed message as clear text—>Do I tick this???? ??????????????

Check/ Tick <i> - Include my certificate</i> - Include my certificate —>Do I tick this???? ??????????????

Encryption Certificate -->What goes here???? ??????????????

Encryption Algorithm -->What goes here???? ??????????????

Check/ Tick - Encryption outgoing messages<i> </i> —>Do I tick this???? ??????????????

NEW WINDOW – Security

Sent 3 options – Store sent messages in this folder OR Don't store sent messages in this folder Drop down menu - Sent Items (Server) OR Sent Items (On my computer) ??????????????

Drafts –Store drafts messages in this folderDrop down menu - Drafts(Server) OR Drafts (On my computer) ??????????????

Junk –Store junk messages in this folderDrop down menu –Junk (Server) OR – other option is in grey
??????????????

Trash Check/ Tick –Move deleted items to this folderDrop down menu –Deleted items (Server) OR – other option is in grey
?????????????? - Drop down menu Never, one week etc

Trash Check/ Tick –Mark messages as deleted ??????????????

Trash Check/ Tick –Do not automatically delete messages??????????????

Trash Check/ Tick –Permanently erasedeleted messages? When outlook closes.
??????????????

OK
—>Press

NEW WINDOW – Server

Check/ Tick <i> </i> —>Download headers only

Check/ Tick <i> </i> —>Except inbox

Check/ Tick <i> </i> —>Sync all imap folders every 2 minutes

Check/ Tick <i> </i> —>Use imap IDLE if the server connection after 29min

IMAP Root folder —> What goes here???? ??????????????

OK
—>Press