Limitations of IMAP

We recommend that people use the official Outlook mail clients to access their mailbox, but people have the option to use alternative mail clients. The configuration information given below should be helpful for using the IMAP protocol to connect to your Exchange Online mailbox. Any mail clients using the IMAP protocol must be configured to use Modern Authentication. At this time, any mail clients using the IMAP protocol that only support basic authentication will not function. 

Note: that IMAP only provides an email connection. You won't receive calendar information through IMAP.

IMAP account settings

Due to the number of different IMAP email clients, it's not possible to provide a menu-by-menu and screen-by-screen set of instructions for configurations. However, once you locate your email client's configuration section, these are the settings you will use.

IMAP Configuration

• Username: yournetid@illinois.edu
• Password: Active Directory password
• Email address: yournetid@illinois.edu
• Incoming mail server: outlook.office365.com
• Incoming mail server: requires authentication/normal password
• Incoming mail server security: port 143 and TLS (Thunderbird uses STARTTLS, other unsupported clients use SSL and 993)
  
• Incoming mail server authentication: oauth2
• Outgoing mail server: smtp.office365.com
• Outgoing mail server: requires authentication/normal password
• Outgoing mail server (SMTP) port: 587
• Outgoing mail server security: TLS (Thunderbird uses STARTTLS, other unsupported clients use SSL)
• Outgoing mail server authentication: oauth2