Epesi Roundcube IMAP settings to access Microsoft Office 365 Email

Microsoft as default setting has turned off IMAP/ POP ports and Epesi e-mail client Roundcube will not connect. 

You have to go into Office365.com Admin and allow IMAP access to external applications, you then wait for changes to propagate.
(from https://www.eduhk.hk/ocio/content/faq-settings-pop-or-imap-access-office-365)

Proper settings for Epesi e-mail account using built-in Roundcube IMAP client are:

Office365 IMAP Server outlook.office365.com
IMAP port 993
IMAP security SSL / TLS
IMAP username Your full email address Your full email address
IMAP password Your Office365 password
Office365 SMTP Server  smtp.office365.com
SMTP port  587
SMTP username  Your full email address
SMTP password  Your Office365 password

From: https://getmailspring.com/setup/access-office365-via-imap-smtp

Troubleshooting tips:

  • Is your Office 365 server ready to accept IMAP protocol clients?
  • If yes then can we use TLS/SSL and username / password combination?
  • If you want to be sure you can use other IMAP desktop client like Thunderbird and test it this way.
  • What port are you connecting on? Check your server's firewall if it is not blocking incoming or connections on this port. Probably your server is not blocking incoming IMAP traffic, you just need to enable IMAP forcing Microsoft to behave like an adult and adhere to open standards.


  • Roundcube, IMAP, Office 365, e-mail, SMTP
  • 1 Users Found This Useful
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