A compromised mailbox is used to send spam, and is one of the most common incidents we handle.
HOW THEY ARE COMPROMISED
A weak or guessable password A password reused on a site that was later breached Malware on a computer or phone that reads saved credentials A phishing message that persuaded someone to enter the password on a fake page
PROTECTING THEM
Long, unique passwords for every mailbox, generated rather than invented Never one shared password across several mailboxes Never a pattern like BusinessName2026 Change passwords when someone leaves Keep the devices that access mail patched and free of malware
SIGNS OF COMPROMISE
Bounces for messages you did not send Contacts reporting strange mail from you Sending limits reached unexpectedly Forwarding rules or a signature you did not create
WHAT TO DO
Change the password immediately, check for unauthorised forwarding rules, update the password on every device, and open a ticket so we can check the account.
