Email Deliverability Consultation

Job ID: 39862281

Budget: $750 – $1,500 USD

I’m not a specialist in this field, but a week ago I successfully ran a continuous send of 1.2 million emails in a single day.
After I modified source code, it suddenly stopped sending

- mail-tester.com scores and DNS (SPF/DKIM/DMARC) look perfect.
- This is not the usual stuff: IP warm-up, PTR, ASN-level blocks, etc.
- My list is legitimate double opt-in.

I need someone who can infer receiving-server policies and propose a solution that actually works. My current suspicion is sending pattern/cadence or content structure.

Please note: I may not be an expert, but I have achieved successful large-scale sends before. Only reach out if you have a concrete hypothesis or experience that fits this scenario.

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I’m not looking for boilerplate advice you can find on the internet—I already know the basics and I don’t think this is that kind of problem.
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No MACRO messages, please.
Related categories: Bulk Marketing DNS Email Marketing Email Handling