This article will guide you on methods to resolve "Email address rejected by server" error which happens in iPhone devices mainly due to wrong mail settings.
The recipient was rejected by the server because it does not allow relaying. Chances are you need to check your outgoing mail server settings. Go to Settings - Mail, Contacts, Calendar and tap on your email account. Tap on "Account, then go down to the "Outgoing Mail Server" section and tap on "SMTP."
If you can't send email try the following: On your iPhone or iPod Touch screen tap Settings and then Mail, Contacts, Calendars.
Select your email account from the list, and then select it again on the next screen.
Scroll down to the bottom and tap on the SMTP field under Outgoing Mail Server.
To fix email rejected by server:
1. Go to Settings > Mail > Accounts and select the account you are having difficulty with.
2. Click on your email address at the top of the screen.
3. Go down to the bottom of the screen where it says SMTP and click on it.
4. Select the Primary Server at the top of the screen.