Malicious attachments and links remain the main payload delivery method for ransomware and credential theft.
How to implement email attachment and link security#
- Block executable and macro-enabled attachment types at the gateway.
- Enable URL rewriting with time-of-click reputation checks.
- Sandbox unknown attachments before delivery.
- For outbound, prefer links to authenticated portals over attachments for sensitive files.
How to verify it worked#
Send a test message to seed mailboxes at Gmail, Outlook, and Yahoo, then inspect the Authentication-Results and delivery headers. Repeat after any DNS or sending-platform change.
Common mistakes#
- Allow-listing partner domains and bypassing scanning entirely.
- Password-protected archives that evade scanning.
Frequently asked questions#
Are PDF attachments safe?
Mostly, but PDFs can carry scripts and phishing links. Sandboxing and link rewriting still apply.