Why am I not receiving invitations to join Teams meetings from my colleagues?

Check who is inviting you:
Confirm that the emails are coming from colleagues with whom you should be meeting, and not from unknown contacts.
Check your email account’s security settings:
Make sure your settings are allowing emails from colleagues to come through.
Check junk and spam folders:
Review junk and spam folders and mark as not junk any emails from your colleagues that have been delivered to your junk folder.
Verify any filters you may have set up:
Confirm that emails from your colleagues are not being filtered out.
Add the sender to your contacts list:
If you recognize the invitation, add the sender to your contacts list before accepting the invitation.