Shared mailboxes are not a security boundary

Shared mailboxes are convenient. They are not a substitute for role-based access or logging.

Common failure modes

• Everyone knows the shared password (when one was set years ago)
• Former employees still have Full Access
• No one owns spam/phishing reported to that address

Cleaner patterns

• Use shared mailboxes without a sign-in password; grant Full Access to people, not a secret
• Use Microsoft 365 Groups or shared channels when collaboration is the real need
• Review Full Access / Send As quarterly

Need a mailbox access cleanup? Open a ticket.