With Microsoft 365, you can generate an app password to sign into an app that does not support multifactor authentication (MFA).
While an app password might seem like a proper solution to an MFA issue in the ShareGate migration tool, we do not recommend using one.
When you use an app password, the migration tool loses access to some Microsoft services, and it can result in slower migrations, unpredictable errors, and other issues.
You will have a better experience with the migration tool if you troubleshoot your MFA issue instead of relying on an app password.
To troubleshoot an MFA issue and contact support for assistance, see Troubleshoot Microsoft 365 connection issues.
Teams and Microsoft 365 Groups
The migration tool uses the Graph API to manage and copy your teams and Microsoft 365 groups.
When you connect to your tenant with an app password, the migration tool cannot access the Graph API and you become unable to copy and manage your teams and groups.
When a global admin consents to the Azure ShareGate migration app, it allows the migration tool to use AppID to tell Microsoft 365 the tenant traffic comes from a migration app. During a migration, AppID helps reduce throttling considerably.
When you connect with an app password, the migration tool cannot use AppID, and you become more susceptible to getting throttled.