Cold Email Deliverability Checklist: 10 Checks Before You Launch a Campaign

Most campaigns that land in spam were doomed before the first email went out. The domain was brand new, a DNS record was missing, or the volume jumped from zero to a few hundred a day. This cold email deliverability checklist covers the ten things worth checking before you press send, in about ten minutes, so you find the problem while it is still cheap to fix.

None of this is a trick. Mailbox providers want to know that you are who you say you are, that people want your mail, and that your sending behaves like a real person's. Each check below maps to one of those three questions.

Part 1: Prove who you are

1. SPF is published and passes

SPF is a DNS record listing the servers allowed to send mail for your domain. You should have exactly one SPF record, and it should include every service that sends for you. Two SPF records on the same domain is a common mistake and makes the check fail. Our guide to SPF, DKIM and DMARC in plain English shows what a correct record looks like.

2. DKIM signs your messages

DKIM adds a cryptographic signature to each message so the receiver can confirm it was not altered and really came from your domain. Send a test message to a mailbox you control, open the original headers, and look for dkim=pass.

3. DMARC exists, even if it starts gentle

DMARC tells receivers what to do when SPF or DKIM fails, and gives you reports. Starting with a monitoring-only policy is fine. A missing DMARC record is not: Google's email sender guidelines require authentication for bulk senders, and a DMARC record is part of that.

4. MX records and reverse DNS look normal

If your domain cannot receive mail, replies bounce and the domain looks thrown together. Confirm the MX records resolve and that your sending IP, if you control one, has matching forward and reverse DNS.

Part 2: Check the reputation you are starting with

5. The domain and IP are not on a blacklist

Run your sending domain and any dedicated IP through a blacklist check. A listing does not always mean disaster, but you want to know before you launch, not after. If you find one, here is what to do next.

InboxRampUp has a free deliverability checker that covers checks 1 to 5 in one pass: SPF, DKIM, DMARC, MX and blacklists for a domain.

6. The domain has had time to build a history

A domain registered last week and used for outbound today has no reputation at all, and providers treat the unknown with suspicion. Warm it first. Warmup means a gradual, steady rise in real sending with real engagement, so the mailbox providers learn that your domain is normal. For agencies running many client domains, we wrote up how to keep track of warmup across all of them.

Part 3: Send like a person

7. Volume is ramped, not jumped

The fastest way to look like a spammer is to go from nothing to hundreds of emails a day. Increase volume in steps, spread sends across the day, and keep each inbox well under a conservative daily ceiling. We cover sensible numbers in how many cold emails per day you can safely send per inbox. If you need more total volume, add inboxes rather than pushing one harder.

8. Complaint rate stays far below the line

Google tells bulk senders to keep their spam complaint rate in Postmaster Tools below 0.30%, and recommends staying under 0.10%. Yahoo publishes similar expectations in its sender best practices. You will not see these numbers for a brand new campaign, which is exactly why the rest of this list matters: your first sends should go to the people most likely to want them.

9. Unsubscribe and sender identity are clear

Make it easy to opt out. Google and Yahoo require one-click unsubscribe for bulk promotional mail, and even if you send below the bulk threshold, an easy way to say no keeps complaints low. Use a real From name, a real signature and an accurate subject line. Our summary of the Gmail and Yahoo bulk sender requirements lists what applies to you.

Part 4: Send to people who want it

10. The list is clean and targeted

Bad addresses bounce, and bounces hurt reputation. Verify addresses before you send, remove anyone who has bounced or unsubscribed, and write for a specific reason you are contacting them. Never buy lists. A smaller, relevant list with a message that fits will outperform a large one every time, and it protects the domain you have just spent weeks warming.

A 10-minute version you can copy

1. Send a test to a mailbox you control and confirm SPF and DKIM pass.
2. Confirm a DMARC record exists.
3. Check MX and blacklists for the domain.
4. Confirm the domain has been warming and the ramp is set.
5. Cap daily volume per inbox and spread sends through the day.
6. Add a visible unsubscribe path and a real signature.
7. Verify the list and remove past bounces.
8. Read the first email out loud. Would you reply to it?
9. Start with a small first batch and watch bounces and replies.
10. Pause and investigate if bounces climb or replies disappear.

How warmup fits in

Checks 1 to 5 are one-time setup. Checks 6 and 7 are ongoing, and that is where most teams slip, because ramping up properly takes weeks and is easy to skip when a launch date is close. InboxRampUp automates that part. Connected mailboxes join a warmup network and send each other mail on a gradually rising, timezone-aware schedule with natural jitter. The receiving mailboxes open, mark read, rescue from spam, star and reply, and you can watch a live reputation score and activity feed for each mailbox. It supports Gmail and Google Workspace, Microsoft 365 and Outlook, and any IMAP/SMTP mailbox.

FAQ

How long should I warm up a new domain before cold outreach?

There is no universal number, because it depends on the domain, the provider and your target volume. Plan for a ramp of several weeks, start with small volumes and increase only while bounces and complaints stay low.

Do I need DMARC if I only send a few hundred emails a day?

Google's bulk sender rules formally apply above roughly 5,000 messages a day to Gmail addresses, but SPF and DKIM are expected from everyone, and a DMARC record is cheap protection against spoofing. Publish one.

Can a checklist guarantee I reach the inbox?

No. Nobody controls inbox placement, and any tool that promises it is overselling. A checklist removes the avoidable problems, so what is left is the quality of your message and list.

What should I check first if a campaign is already landing in spam?

Start with authentication (checks 1 to 3), then blacklists and volume. If it has already happened, follow our step-by-step spam recovery plan.

Start with the free check

Run your domain through the free deliverability checker to cover SPF, DKIM, DMARC, MX and blacklists in one go, then start a free trial to warm up the mailboxes you will send from. No credit card needed.