Have you tried the settings posted here?:
https://futurequest.net/forums/showt...946#post185946
"Use mail.QuestMail.net as your POP and SMTP Mail server hostnames. This option removes the certificate Mismatch issue as the SSL/TLS Certificate used for mail.QuestMail.net is issued to QuestMail.net
You must use your full email address,
user@yourdomain.com (as an example), as a username when using mail.QuestMail.net as a mail server hostname."
If you are using Secure Email then the ports would need to be:
Port 995 Secure POP
Port 993 Secure IMAP
Port 465 Secure SMTP