Mail App keeps hanging (not crashing) on Yosemite 10.10.3

Solution 1:

I have had the same problem since updating to Yosemite. None of the advice posted on any website seems to work until I tried this and so far Mail is working fine https://miapple.me/fixing-mac-os-x-10-10-yosemite-mail-not-responding/ give it a shot

Solution 2:

I have seen this issue quite a few times and none of the solutions seemed to work very long. The issue kept on returning. I do think I found a cause - although I only test 4-5 times. It seems to be an issue that keychain access is open - strangely enough :) Close keychain down and mail works fine again without deleting anything

Confirmed. Might have to wait 2 mins or so before the system processes the action of closing keychain.