I've been an iPhone user for years. I've always had multiple POP email accounts, multiple SMTP servers, etc. and it always worked great. Sure, I'd occasionally run into an issue where one account would trip-up on outgoing messages for a few minutes, but it always resolved its self. Suddenly, ALL my email accounts stopped sending today; they instantly go to the Outbox with the pop-up message "The recipient ___ was rejected by the server". They don't even try to send. I have done tons of tests including the following: -Try different recipients on different TLDs and server -Try different SMTP outgoing servers to make sure it wasn't just the "primary" that was failing and holding things up -Try different connections (4G, LTE, WiFi home, WiFi public, etc.) -Every combination of the above -Restore iPhone to earlier backup when outgoing email did work After all that, I have the same problem and nothing changes it. All I can find in googling is info related to first-time set-up, or stuff about "double check your settings" but in my case, nothing changed and all the email servers are active... it's just like the phone stopped even trying to send. (In fact, when I tried adjusting SMTP settings, it verified the settings and appeared to connect to the outgoing server without problem, then it still refused to send the messages.) Any ideas out there would be appreciated!