If you're sending through a GMail account, it's the tablet's configuration, but if not it could also be the server's configuration, and there's nothing you can do until the owners of that particular email service (Yahoo, Microsoft, your company - whichever one it is) fixes it.
The first try in this would be to delete the email account in your email app, then add it again (as an existing account), and let the app set it up automatically. If that fixes it, it was an SMTP setting n the tablet (SMTP is the protocol used for sending an email). You won't lose your emails, although it might take a few minutes for the app do download all of them again. (Trust me - I've been through this twice in 2 days due to a supposedly bricked phone. When you've been in the business since before cellphones, sometimes when level 2 tech support says it can't be fixed, that's my cue to fix it. I think I got everything back the way it was now.)
04-10-2018 04:26 PM