Have users turn on 2-step verification and add an app password. For %BRAND_OFFICE_365_SHORT% to connect to Gmail mailboxes, ...

Have users turn on 2-step verification and add an app password. For %BRAND_OFFICE_365_SHORT% to connect to Gmail mailboxes, the migration file must provide the sign-in credentials for each Gmail mailbox. These credentials must include an app password, which users create using Gmail's 2-step verification feature. If you provide a user's regular password in the migration file, Gmail doesn't allow %BRAND_OFFICE_365_SHORT% to connect to the mailbox. For users to create an app password, %BRAND_GOOGLE% administrators first need to enable 2-step verification for users. Gmail users can then turn on 2-step verification and create an app password.