Edit: Still using K9 Mail. The most annoying thing about this app is deleting multiple emails. Rather than press and hold to enter into a ""select mode"" where you then tap all your emails you want to delete  you have to press and hold each email and choose ""select"". This takes ten times longer to simply delete multiple emails. It's rather painful amd annoying. All of a sudden I could no longer send email  only receive. I went to the server settings for outgoing mail  and clicked next and immediately got an error. I didn't notice at first  but after the update  www was added in front of my outgoing server. removed the www and it worked fine as it should. Thought I'd post this in the review section in case others come here with the same issue
February 19 2017