Virus scanning
Mail to your mailboxes from other servers is scanned for viruses as it arrives. A message with a virus is refused, so it never reaches anyone whose mail is scanned, and the sender is told.
Who is scanned
Your provider decides whether scanning is on for everyone, on unless you turn it off, off unless you turn it on, or off for everyone. When you can choose, tenant owners and admins choose in the tenant manager at /manage under Mail → Virus scanning:
- Default follows your provider's choice.
- Scan or Do not scan chooses for all your domains left on Default.
Each domain can choose for itself on its page (Domains → the domain → Virus scanning); its choice wins over the tenant's. The card shows, for the tenant and each domain, whether mail is scanned and why. When your provider decides for everyone, the choice is greyed out.
What happens to a message with a virus
- Sent only to scanned mailboxes: refused. The sender gets an error saying it contains a virus, and the virus's name.
- Sent to scanned mailboxes and others too: the others get it, the scanned ones do not.
- Allowed senders are scanned too: allowing a sender skips spam filtering, never virus scanning.
- Mail your people send is scanned too when your provider has that on: a virus is refused and never sent.
To see what happened to a message, open it in the message trace: its Virus scan step says whether it was scanned, what was found, and why a mailbox was or was not scanned.