Your cold email agency is probably burning your domain

Hey,

I'm going to save you $2K-$5K/month and potentially your entire email deliverability.

Here are 3 signs your cold email setup (or your cold email agency) is burning your domain:

Sign #1: They're sending from your main domain.

This is the biggest red flag. Your main domain — the one your clients email you on, the one on your website, the one your team uses every day — should never send cold email.

If it gets flagged as spam (and at scale, it will), your entire business email reputation tanks. Client emails going to spam. Proposals going to spam. Everything.

The fix: buy 3-5 secondary domains. Set up SPF, DKIM, and DMARC properly. Warm them for 2-4 weeks before sending a single cold email.

Cost: $10-15/year per domain. Cheap insurance.

Sign #2: They're sending more than 30-50 emails per inbox per day.

The temptation is to send more. More emails = more replies, right?

Wrong. Eric Nowoslawski tested this extensively. Reply rates collapse above 30 emails/day per inbox. You get more volume but worse deliverability, worse reply rates, and more spam complaints.

The math: 5 inboxes × 30 emails/day × 5 days/week = 750 emails/week. That's plenty. Quality over volume.

If your agency is blasting 5,000-10,000 emails/week from 2 inboxes, they're cooking your sender reputation for short-term vanity metrics.

Sign #3: They use HTML templates with tracking pixels and links.

Plain text emails. No tracking pixels (they trigger spam filters). No link tracking in the first email. No images. No HTML formatting.

Your cold email should look like a message from a colleague. Not a marketing email from HubSpot.

If your agency sends cold emails with headers, logos, colored buttons, and tracking pixels — they're prioritizing their reporting over your deliverability.

The right setup:

Here's exactly what we use:

→ Instantly for sending (handles inbox rotation, warmup, and analytics): https://refer.instantly.ai/gxqjr1iyn1bd

→ Reoon for email verification before any send (keeps bounce rate under 3%): https://www.reoon.com/email-verifier/?inv=c237mb14

→ 3-5 secondary domains with proper DNS configuration

→ 2-4 week warmup period before sending

→ Max 30 emails/day per inbox

→ Plain text only. No tracking pixels. No links in email 1.

→ 4-5 step sequences, each under 75 words

The result:

Open rates: 60-80% (because we're not in spam)

Reply rates: 5-15% (because the emails look human)

Positive reply rates: 2-8% (because the targeting is signal-based)

Compare that to the "spray and pray" agencies that promise 10,000 emails/week and deliver 0.5% reply rates. Same effort. Wildly different results.

What to do right now:

1. Check if your main domain is sending cold emails. If yes, stop immediately.

2. Go to mail-tester.com and send a test email. If your score is below 8/10, you have a deliverability problem.

3. If you're working with a cold email agency, ask them: "How many emails per inbox per day are you sending?" If the answer is above 50, you have a problem.

If your domain is already burned, it takes 2-8 weeks to recover. Better to know now than after another month of damage.

Reply to this email with your mail-tester score. I'll tell you if you have a problem.

Keep dominating,

Tanyo