In case the multi-factor authentication is enabled for your user account, you can use an app password to login. Just use this password instead of your usual password to connect your email to Onpipeline.

An app password allows to connect Onpipeline to your Office365 account securely! Go to https://account.activedirectory.windowsazure.com/AppPasswords.aspx (login as user) to create one in 1 minute.