iPhone X-APOP authentication support and secure connection failed

When we add a new POP email account to iPhone, we got an error which said:

Secure Connection Failed - the certificate for user@domain.com may be invalid

Then, it asked if he wanted to Cancel or Continue.

Whenever we clicked Continue, the verifying POP account information just continued processing. It was like the iPhone freezed or hanged.

please perform the following steps to add a new POP email account

1. Click Settings
2. Click General
3. Click Auto-Lock
4. Click Never (don’t let it go to sleep)
5. Go back to Settings
6. Click Mail
7. Click Add Account
8. Click Other > POP and fill in the required information
9. Click Save and wait (Verifying POP account information)
10. Click Continue when Secure Connection Failed is prompted
11. Click Continue/Yes if you get either of these message:
* SSL connection failed, would you like to try without it?
* Secure Connection Failed…user@domain.com…invalid
12. It should complete and you’ll see your account added but to complete…
13. Click the new email account
14. Scroll down and Click Advanced
15. Turn off: Use SSL (both incoming and outgoing)
16. Make sure Authentication is Password
17. Set Server Port for Outgoing Settings
18. And you’re done!

Your outgoing port may be different from what I have mentioned so check with your Technical Support or Website Hosting administrator.

In addition to iPhone email encounters, also got this message when we checking email :

Cannot Get Mail
The POP Server “mail.domain.com” does not support X-APOP authentication. Please check your account settings and try again.

If you get this message, you’ll need to set the Authentication to Password. Please check your settings, it was set to MDA-5albeit only having MD5 Challenge-Response and HTTP MD5 Digest in the Authentication Settings. Anyway, the Authentication settings is found in the Advanced area of your email accounts. This may only happen to your default email account if you’re on POP.

So if you experience the iPhone mail X-APOP authentication support or secure connection failed, I hope this helps you too.

p.s: After you’re done, you can set your Auto-Lock back to your own preference.