Many of our IMAP users have questions about how to add their IMAP email accounts in Polymail. IMAP server settings can vary based on your provider, so we've put together some basic guidelines and hints to help you along the way! 
Your IMAP Port should be 993. We absolutely require SSL. 
Your SMTP Port can be 465, 587, and in some rare cases, 25. We recommend trying ports in this order:
  • For 465, Check the SSL option
  • For 587, Check the STARTTLS option
  • For 25, Check the STARTTLS option.
If you receive an X509 error, it means you should check the Insecure SSL option. You may need to do this for IMAP, SMTP, or both. (Insecure SSL is generally used when the domain name you're using doesn't match the host's name or for self-signed certifications.)
We hope that's useful! If you go through these steps and still have trouble, shoot us an email at We'll be happy to help you get up and running!