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Sender Requirements Checklist: Is Your Cold Email Setup Ready to Send?

The short answer

Before the first send, check four things: your domain passes SPF, DKIM and DMARC, your spam complaint rate is far below 0.3%, your volume per inbox stays low, and every address is verified. Gmail and Yahoo require authentication from bulk senders and set the same 0.3% complaint ceiling. This page is free to read and built to print.

Updated

What do Gmail and Yahoo require?

Requirement What it says Source
Authentication Bulk senders (about 5,000 or more messages a day to personal Gmail accounts) must authenticate with SPF and DKIM and publish a DMARC record, with a policy of at least p=none Google, Email sender guidelines FAQ
Spam complaint rate Google asks senders to stay below 0.1% and says 0.3% or higher seriously hurts delivery Google, Email sender guidelines FAQ
Same ceiling at Yahoo Yahoo's Sender Hub sets the same 0.3% ceiling Yahoo Sender Hub, best practices

At 0.3%, that is three complaints per thousand emails sent. Cold senders usually send far fewer than 5,000 messages a day, but setting up all three records is free and protects low-volume senders too.

What do you check, and who fixes it?

Check You pass when If it fails
SPF One SPF record per domain, listing every service that sends as you Merge duplicates; add the missing tool; ask whoever manages DNS to confirm the lookup limit
DKIM Every sending tool signs with your domain's key Publish the key each tool gives you in DNS
DMARC A record at p=none or stricter, with a reporting address Publish one; tighten to quarantine only after reports are clean
Spam rate Under 0.1% in Google Postmaster Tools (it shows data only at meaningful daily Gmail volume) Stop, fix the list and the message, then resume

How do you run the two-minute check?

  1. Send a test from the inbox you prospect with to a personal Gmail account.
  2. Open it, click the three-dot menu next to reply, then "Show original."
  3. Read the SPF, DKIM and DMARC lines. You want PASS on all three, and the domain next to SPF or DKIM should be yours, not your sending tool's.
  4. On a FAIL, capture it and send it to the person who owns your DNS, with the list of tools that send as your domain.

What are our sending guidelines?

These are our planning numbers, not provider limits:

  • Separate sending domains, kept apart from the domain your team uses every day.
  • 2 inboxes per domain and 4 inboxes per rep.
  • About 30 sends per inbox per day, over 21 sending days a month. One rep sends about 2,520 emails a month.
  • Warm new inboxes before sending at volume.
  • Verify every address before it goes into a sequence. Our guideline is to pause and re-verify when bounces pass 2%. Google and Microsoft publish no bounce threshold.

Checklist

  • [ ] SPF is one record and covers every sending tool.
  • [ ] DKIM is on in every sending tool.
  • [ ] DMARC is published at p=none or stricter, with reports going somewhere.
  • [ ] The Gmail check shows PASS, PASS, PASS with your own domain.
  • [ ] Sending domains are separate from your main domain.
  • [ ] Inboxes are warmed and capped at our guideline of 30 a day.
  • [ ] Every address is verified, and you watch bounces.
  • [ ] You re-run the check whenever you add a tool.

Where to go next

The sending days, sends per inbox, inboxes per rep and touches per contact on this page are our house assumptions, with one line on why we use each.

Sources

Research and vendor pages accessed October 1, 2026.

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