I have an iPhone 5c that I recently upgraded to iOS 10 and now it won't send emails. No issues previously. Does anyone know if this is a know issue and what the fix might be? Emails I tried to send from my home wi-fi say "an error occurred while delivering this message" while the ones I tried to send while away from home say "the connection to the outgoing server failed..."

Also, I thought that if an email couldn't be sent on one SMTP server it will select the next on the list or one related to the network service provider. Any idea where I can get more info on how this actually works?