Guide · Outbound
Cold email infrastructure checklist: 20 checks before you send
Domains, mailboxes, DNS, warm-up, limits, lists and monitoring — the checks to run before a campaign goes live.
Run these 20 checks before any cold email campaign goes live. Most delivery problems we see come from skipping one of them. The checklist is ordered the way a setup is built: domains first, monitoring last.
A note on responsibility. This checklist reduces technical risk. It does not make an irrelevant message welcome. Send only to business contacts who are likely to find your message relevant, identify yourself clearly, and make opting out easy. Rules differ by country, so take legal advice for your markets.
Domains
- Separate sending domains. Outreach runs on domains related to your brand, not on the domain your company uses for everyday email.
- Credible names. Sending domains are recognisably connected to your brand. Random or misleading names undermine trust.
- Web redirect. Each sending domain redirects to your main website, so a prospect who checks it finds a real business.
- Enough domains for the volume. The number of domains and mailboxes is planned from your target daily volume, not guessed.
Mailboxes
- Real sender identities. Each mailbox belongs to a named person with a complete profile and signature.
- Replies reach a human. MX records are set and replies are monitored, whether in the sending platform or forwarded to the team.
- You own the accounts. Mailboxes sit in your own Google Workspace or Microsoft 365 tenant, or with a provider whose terms you have read.
DNS and authentication
- One valid SPF record per sending domain, within the 10-lookup limit.
- DKIM signing enabled in the mailbox provider and verified with a test message.
- DMARC published with a reporting address. Start with
p=nonewhile you confirm everything passes. - Alignment confirmed. A test message shows SPF, DKIM and DMARC all passing for the From domain. Our SPF, DKIM and DMARC guide explains how to check.
- Custom tracking domain, if you use open or click tracking, so links do not point at a domain shared with other senders.
Warm-up and sending limits
- Gradual ramp-up. New mailboxes start with low daily volume and increase over several weeks.
- Per-mailbox daily limits are set in the sending platform and kept conservative. There is no universal safe number; your platform’s guidance and your own results set the ceiling.
- Sending windows match the recipients’ business hours and time zones.
Lists
- Every address verified shortly before use, with invalid addresses removed and risky or catch-all addresses kept separate.
- Exclusions applied: existing customers, open deals, competitors and everyone who has previously opted out.
Campaign settings
- Stop on reply. A reply from a contact, or anyone at their company if you prefer, stops the sequence for them.
- A clear way to opt out in every email, honoured promptly across every campaign and tool.
Monitoring after launch
- A weekly health check: bounce rate, reply rate, any mailbox paused by the platform, blocklist status and, where available, Google Postmaster Tools data. Pause first and investigate second if anything moves sharply.
If several of these are already failing on a live campaign, see our deliverability service. For new setups, our email infrastructure service covers checks 1 to 15.
Need a hand with this? Our Cold email deliverability service covers this work end to end.
Introductory call
Let’s talk about your outreach and follow-up.
A 30-minute call to understand your requirements, current challenges and goals — and whether we’re a good fit.
- Pick a time that suits your time zone
- Talk through your setup and goals
- Discuss possible approaches — no obligation