Inside MxGuard: the layered filtering pipeline explained

Business Email doesn't rely on a single spam trick — every inbound message runs through MxGuard, Transcom's own AI mail gateway, which stacks several independent checks so that anything one layer misses another catches.

The layers, in order:

• DNSBL (DNS blocklists) — the sending server's IP address is checked against reputation lists of known spam sources. Persistent offenders are turned away at the door.
• URIBL (URI blocklists) — the links inside a message are checked, not just where it came from. A message from a clean server that points at a known scam or malware site is still caught.
• SPF, DKIM and DMARC — authentication checks that confirm the sender really is who they claim to be, so forged and spoofed mail is spotted.
• Machine-learning classifier — an AI model scores the content of each message on the patterns that separate genuine mail from spam, phishing and scams. It keeps improving as mail patterns change.
• ClamAV virus scanning — attachments and payloads are scanned for malware before anything reaches your mailbox.

Because the layers are independent, a message has to look legitimate on every count to land in your inbox. There is nothing for you to install, update or tune — the whole pipeline runs on Transcom's gateway and is maintained for you.