Hi,
Do you mean you cannot find the option to flag an item for follow up in Outlook? Generally, if your account type supports Follow Up Flag, you can find the option on the Ribbon:

However, since the IMAP protocol doesn't support the Category and Flag properties on messages, if you are using an IMAP account, there will be no Category button on the ribbon, and you may only have limited Flag options. See:

To verify whether you are using an IMAP account, go to File > Account Settings, check the
Type column for your account.

Regards,
Steve Fan
Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact
tnsf@microsoft.com.

Click
here to learn more. Visit the dedicated
forum to share, explore and talk to experts about Microsoft Teams.