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

This just  smtp not working. Receiving fine, but can't reply. I'll use Thunderbird till Apple release a [working] update.

Mail freezes for me - ON LAUNCH - when trying to load all emails. Sometimes it will load none. Sometimes just the headers. I quit and it hangs. I force quit and relaunch. At some point, it will work. This is after update to 10.10.4 on iMac (27-inch, Late 2013) 3.4 GHz Intel Core i5.

Same problem here as well. Broke in 10.10.4 latest beta and still broken in 10.4.4. Was working in earlier betas. SMTP will not work with SSL. If I turn SSL off I can send mail. But this is unacceptable. Broke in latest iOS update on phone as well.

A SHORT-TERM SOLUTION.   Press and HOLD shift while LAUNCHING the MAIL application and HOLD IT until Mail atarts up.  Worked for me...

Since updating to 10.10.4 on my rMB mail would freeze 2/3 of the time when trying to connect to servers, and trying to quit would just hang or beach ball (had to force quit). Using the shift-trick above got me past it for now. But this is pretty bad, mail had simply stopped working. If this was my only computer I would have been in deep trouble (fortunately I am keeping my MBP 17 on 10.9).

Seriously the quality of software seems to be rapidly decreasing here. I am not a naysayer but having waited for a new OS on the rMB for a while, and getting this as the update to fix issues and have it just brick Mail doesn't make the product feel very "special."

FYI:

I can send mail fine on my 10.10.3 backup disk, but 10.10.4 doesn't work, so something has changed with the latest update. I spent 2 hours on the phone with a helpful and knowledgeable Apple Support rep, but still no fix. I've tried all the fixes suggested on the other threads, including deleting keychain entries and editing preference files, and just about every combination of settings. My ISP suspects a bug in the OpenSSL libraries that were updated, but I have no idea.

See my solution above:

A SHORT-TERM SOLUTION.   Press and HOLD shift while LAUNCHING the MAIL application and HOLD IT until Mail atarts up.  Worked for me...

Thanks for this tip. Sadly, the shift key trick doesn't work for me (Macbook retina - 2015). Nor does altering the "Automatically detect and maintain account settings" as other have tried. Hope a fix from Apple emerges soon.

Okay, I finally got it working for me. I created a new account, identical to the old one (using the "+" below the account list in Mail preferences, Accounts tab). Apparently letting it set up everything fresh reset something, or it's possible one of the many other things I tried earlier was a factor. It apparently re-seting up the account with the same info overwrote the original settings, as it did not create a second account. This new account now works, so I'm able to send email again. Finally!

I'd be interested in hearing if anyone else has luck with this process.

FYI, I just looked in my "Sent" Mail folder, and it's empty now, so I may have to recover those sent emails from my backup. Though it's possible I lost them while trying something else.

FYI, here's how I got email working on my iPad with iOS 8.4:

I deleted my email account on the iPad, and created a new one. It first spent 10 minutes "Verifying", then came back with a message that it could not set it up using SSL, and offered the option of going without SSL, which worked. I can now send and receive email on my iPad, though it may not be secure. I may try setting it up again in the future, to see if I can get SSL back.

A fresh install of Thunderbird gives me the same problem as with Apple Mail. 'Can't connect to Gmail SMTP server.'

Thus far none of the solutions offered make any difference to the situation. Many thanks for the suggestions, though.

I have to say that 10.10.4 is buggy - VERY buggy. Everything it was meant to fix (which wasn't broken on my 10.10.3) - network, internet, SSL, mail - all now pants.

Poor show, I'm afraid.

Downloaded and installed Postbox - exactly the same problem. I think 10.10.4 has messed with SSL or something. IMAP accounts work OK, but my business account is POP. I'll have to run a weird reply-by-cloud system until Apple get this farrago sorted. I certainly won't be updating the MBP or moving to IOS 8.4 on other devices.

I upgraded yesterday.  I can receive but not send.  Anyone know how to fix this?