Microsoft may block an email account that seemed to be sending a large volume of email marked as spam or engaging in other suspicious behavior. To unblock the account:
- Change the user's PennKey password. If not already enrolled, encourage the user to enroll in Two-step Verification to better protect their PennKey.
- Change the user's Windows and/or Mac login password(s).
- Check the user's mailbox for any unauthorized mailbox forwarding rules.
- Do a malware scan of the local computer(s) used by this user.
- After completing the above 5 steps, submit a request to ISC Client Care, help@isc.upenn.edu, to have the account unblocked.