The Ultimate Cold Email Infrastructure Checklist (2026 Edition)
You can write the best Shakespearean sales pitch in history, but if your SPF record is misaligned, no one will ever read it. Deliverability is physics, not art.
1. The "Burner Domain" Strategy
Never outbound with your main domain. This is Rule #1. If you burn your main domain's reputation, your invoices to clients won't go through. Your internal emails will vanish.
We buy "lookalike" domains (e.g., if you are acme.com, we buy getacme.com). They protect your brand shield.
2. The Holy Trinity of DNS
- SPF (Sender Policy Framework): The ID card. It tells the receiver "This IP is allowed to send email for this domain."
- DKIM (DomainKeys Identified Mail): The wax seal. A cryptographic signature that proves the email wasn't tampered with.
- DMARC: The bouncer. It tells the server what to do if SPF or DKIM fail (Reject them!).
3. The 14-Day Warmup Rule
You cannot buy a domain on Monday and send 1000 emails on Tuesday. You must "warm up" the inbox.
How we do it: We use automated warmup pools where your inbox talks to other high-reputation inboxes.
- Day 1: 2 emails
- Day 5: 15 emails
- Day 14: 40 emails (Ready for launch)
4. The "Spam Trap" Danger Zone
Not all invalid emails are created equal. "Spam Traps" are the most dangerous. These are pristine email addresses owned by blacklists (like Spamhaus) that have never been used for a real signup. If you email one, you are instantly flagged as a spammer.
Legacy lists are full of these. You need a multi-stage cleaning process (we use MillionVerifier followed by NeverBounce) to filter these out before they ever touch your sending domains. One bad apple literally spoils the whole bunch.
5. The Art of Spintax
It's not just about technical settings. It's about content fingerprinting. If you send 5,000 emails that are identical, Google signatures the content and blocks it.
You need advanced Spintax (Spin Syntax). Instead of saying "Hi", you say {Hi|Hello|Hey}. Instead of "I'd love to chat", you say {I'd love to chat|Open to a call?|Do you have time?}. TenX infrastructure includes "Spintax on Steroids" setup that generates millions of unique permutations of your script.