The B2B outbound stack

Cold email lives or dies on infrastructure. Get it wrong and you do not just lose a campaign — you burn the domain your real customers reply to. The whole stack is built around one rule: keep outbound completely separate from your main domain.

Buy dedicated sending domains, never your primary one. Run the mailboxes on Google Workspace or Microsoft 365, and drive them with a sequencer — Instantly for volume and deliverability tooling, or lemlist if you want richer personalization. Warm every new mailbox before it sends in anger; most modern sequencers now build warmup in, so you rarely need a separate tool like lemwarm.

Verification is non-negotiable. A bounce on cold mail is a direct hit to reputation, so run every address through MillionVerifier or ZeroBounce before it enters a sequence. Prospect data comes from Apollo or ZoomInfo, depending on your budget and coverage needs.

The principle that ties it together: your main domain is for replies and real relationships. Cold outreach happens on domains you can afford to lose — and, done right, rarely do.