Rejected providers so far:
- GreenCloudVPS - 4/10 Gmail delivery, SPF passes but DKIM fails intermittently
- Hetzner - 6/10, better but newsletters still hit promotions tab
- Leaseweb - 2/10, complete disaster, their /24 is warm at best
Running my own mail on a Time4VPS colo box, Xeon E3 v6, 45W idle. 1U Supermicro. Delivery score 9/10 to Yahoo, 5/10 to Gmail. Same DNS records, same Postfix config, same everything.
SPF: pass
DKIM: pass
DMARC: p=quarantine rua=mailto:...
Reverse DNS: mail.example.com matches banner
No blacklist hits on my IP specifically.
MXToolbox shows my /24 neighbor 192.0.2.47 on Barracuda RBL. Could a neighbor drag down my reputation? IP is 192.0.2.83, same /24, different /26 even.
Dedicated IP from Contabo is €8/mo more but I'm already burning 180W at the rack. Rather not spend more if it's not the fix.