Most of the time the problem relates to:
Wrong port number
Server does not have a valid SSL/TLS connection.
RESOLUTION
1. Try the IMAP connectivity test via https://testconnectivity.microsoft.com/tests/O365Imap/input
This is the host.name.com that typically has the port number 993 attached.
This only tests the IMAP side, not the SMTP side, nor does it test the SSL certificates.
Ensure Authentication is set to Basic
Verify the result of your test and confirm it passes. If it shows an error please reach out to your email admin.
Confirmed: We now know the username / password and port 993 are correct.
2. Run the SMTP test via https://www.gmass.co/smtp-test
This is the host.name.com that typically has the port 465 / 587 associated with it.
Choose SSL under security.
Verify the result of your test and confirm it passes. If it shows an error please reach out to your email admin.
Please ensure both these tests pass in order to connect an IMAP account with Pulse360.