Sometimes users have a mail application (such as Mozilla Thunderbird, Apple Mail, etc.), which connects to your U of L email account via IMAP (rather than Microsoft Exchange). If you are using an IMAP mail client, you will need to manually reconfigure the account settings so that it can connect to your U of L email account on Office 365.
The settings that you need to use for IMAP access on Office 365 are as follows:
Username = your full email address (including the @uleth.ca part)
Password = your normal U of L email password