Q: Mail not working after update OS X 10.10.4 and IOS 8.4

The work-around  to go to Preferences / Accounts - then for each mailbox go to the advanced tab and tick or untick  "Automatically detect and maintain account settings" works for me, until I restart Mail.  Then I have to do this all over again.

Wow! Totally fixed mine. All my gmail IMAP accounts were failing after the update, saying they were unable to sign in and that I should check my username and password. I checked the box and now everything works. THANK YOU.

My SMTP failures were apparently caused by the almost simultaneous switchover by cableone of its SMTP servers mail.cableone.net to smtp.gmail.com and my installation of 10.10.4 on July 1.

I could not fix it but reported to Apple and installed Mozilla Thunderbird... works fine but prefer Mail

This seems to be working for me too, bit flaky its worked then stopped, then worked and stopped, but its getting more reliable and does seem at least get things moving again. Thanks Damo

""""The way I fixed it was to go into preferences for Mac Mail, and then Accounts.  Then for each mailbox, go to the advanced tab and tick "Automatically detect and maintain account settings".

I then saved the configuration changes and restarted Mail and my accounts started working again.""""

The problem is with the update from apple store

You can download a new update from apple

OS X Yosemite 10.10.4 Update

After installation you can receive and sent messages again

Sounds good - are you sure about this? I'm a tad uneasy about installing something else!

Nope - I did that. No difference. The problem is within how 10.10.4 handles SSL, apparently.

As I said - roll on 10.10.5!

I just tried the below. Sadly, it has not resolved the problem for me.

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The problem is with the update from apple store

You can download a new update from apple

OS X Yosemite 10.10.4 Update

After installation you can receive and sent messages again

_______

I only updated to 10.10.4 yesterday 4th July. The update you recommend is dated 30th June, so it has to be the same update that I now have. I still get the blue ball when opening Mail. It has been going on since 10.10.3 but now happens on most occasions. But I haven't tried the fix of holding Shift whilst opening Mail.

I have the problem of not being able to send or receive using Apple mail with my ISP.  DSLextreme.  I repaired permissions and downloaded the OS X 10.10.4 combo update and applied it.  This did not fix the problem.  Also ran Keychain first aid. No help.

Jim

from watching network traffic, it appears that maybe apple has started requiring tls 1.2 for smtp. i can connect to a postfix or sendmail server with tls 1.2 available, but not sendmail with only tls 1.0.

and doing a little more digging, it looks like it can talk to a system which can do sslv3.

hopefully this was just a mistake of some sort and it will be patched shortly.

Same Problem

Same problem for me,has anybody found a way to fix it?

This worked for me.  Thanks!