Cold email glossary.

SPF / DKIM / DMARC

DNS records that prove your mail really comes from your domain, and say what to do when it doesn’t.

Alignment

When the domain in your From address matches the domain SPF or DKIM checked. DMARC needs at least one to align.

MX record

Tells the world which provider receives your domain’s mail. It also tells you a prospect’s provider.

Tenant

Your organisation’s account at Google or Microsoft. Microsoft can restrict a whole tenant at once.

Secondary domain

A look-alike domain, such as getbrand.com, used only for cold email so your main domain stays safe.

Warm-up

Low-volume automated email between mailboxes that builds sending history before cold sending.

Seed / placement test

Sending to test inboxes to see inbox versus spam. Useful, but noisy for B2B.

Provider matching

Sending Google-run prospects from Google mailboxes and Microsoft-run ones from Microsoft mailboxes.

Catch-all

A domain that accepts any address, so individual mailboxes can’t be verified normally.

Waterfall enrichment

Running several email finders in turn and keeping only results a verifier confirms.

Blocklist

A public list of domains or IPs flagged for spam, used by filters worldwide.

Spam trap

An address that exists only to catch senders using old, scraped or bought data.

Bounce rate

The share of emails rejected as undeliverable. Healthy is under 1%; over 2% means stop and re-verify.

Spam complaint rate

The share of recipients who mark you as spam. Act over 0.1%; Gmail’s ceiling is 0.3%.

List-Unsubscribe header

A hidden email header that gives recipients a one-click unsubscribe button in their inbox.

Signal

A recent, real event showing a prospect has the problem now.

Positive reply

A reply agreeing to a next step or asking for what you offered.

Speed to lead

Time between a positive reply and your answer.

Emails per meeting

How many sends it takes to book one meeting. Every scaling decision rests on it.

Verified market

The qualified people you can actually reach, after finding and verification.

CAN-SPAM

The US law for commercial email: truthful headers and subject, a postal address, ad identification and a working opt-out.

PECR

The UK’s rules on electronic marketing, alongside UK GDPR.

CASL

Canada’s anti-spam law, which generally requires consent.

DPDP Act

India’s Digital Personal Data Protection Act; its Rules phase in by 13 May 2027.

Missing a term? Tell me and it goes into the next update.

Next: set up SPF, DKIM and DMARC, or find out why your emails land in spam.