PTR hostname is generic (cloud provider default)
Your IP has a PTR record, but it looks like a cloud provider default (ec2-X-X-X-X.compute.amazonaws.com). Receivers downgrade trust.
Generic cloud hostnames flag as 'opportunistic sender' — not spam exactly, but not trusted. You may see mild deliverability degradation and Promotions-tab placement at Gmail.
What causes it
- You spun up a cloud instance and didn't customize the reverse DNS.
- Your provider doesn't allow custom PTR records on your tier.
- You accepted the auto-generated hostname at setup.
How to fix it
Step 1: Request a custom PTR
AWS: EC2 → Elastic IPs → Reverse DNS request form. DigitalOcean: Networking → PTR records. Hetzner: Server detail → Reverse DNS. Linode: Network tab → Edit RDNS. Most require you to prove you control the forward DNS first.
Step 2: Match PTR to HELO
Set your PTR to mail.yourdomain.com (or wherever you HELO from). Then verify A record of mail.yourdomain.com points to your IP.
Step 3: Consider dedicated mail infrastructure
If you can't get custom PTR on your current cloud, that's a sign to move mail sending to a managed transactional service.
Fixed it? Run a fresh test to confirm.
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