The recipients were rejected by the server
Cannot send e-mail. get the recipients were rejected by the server. Any answers that work would be nice! Why don't Apple investigate as it appears to be a common problem!
iPad, iOS 7.1
Check the outgoing mail server setting. Make sure that your username and password are in there.
Settings>Mail, Contacts, Calendars>Your email account>Account>Outgoing mail server - tap the server name next to SMTP and check in the primary server and make sure your username and password are entered and correct - even if it says that the password is optional.