Updating Password Authentication Method on Your iOS Device
To ensure your iPhone, iPad, & iPod's SMTP settings are properly configured:
1. From the home screen on your device tap Settings, and then Mail, Contacts, Calendars.
2. Then tap the email account under Accounts.
3. Tap Account.
4. Scroll down and tap SMTP under Outgoing Mail Server.
5. Tap on your Primary SMTP server (secure.emailsrvr.com)
6. Tap Authentication.
7. Ensure Password is selected rather than MD5 Challenge-Response.
8. Tap the button on the top left to go to the previous screen, then click Done.