Enable SMTP Authentication for mobile devices iPhone

Step 1. Go to Settings, Mail, Accounts.
Step 2. Select the email address.
Step 3. Tap Account.
Step 4. Look for Outgoing Mail Server and tap SMTP.
Step 5. Tap the Primary Server.
Step 6. For the Authentication, select Password and tap Done. smtp-atuhentication-iphone-password
Step 7. Go back to the Account and tap Advanced.
Step 8. For Authentication, select Password.