This thread went from Contabo blacklists to debating Swiss email philosophy. Classic.
What do you use for email when your host's IP is blacklisted?
I'm in Vilnius and found a local provider with clean IPs for 4 EUR a month. Run my mail relay there, main server is elsewhere. Two servers, two problems, but at least the mail gets through. Sometimes the local shops are the answer.
In Turkey we have similar problem with Hetzner IPs often dirty. I use a cheap VPS from a local datacenter in Istanbul just for mail relay. 25 TL per month, IP is clean because they actually police their network. Local solution for local problem.
Local relay VPS is the pattern I'm seeing here and it makes sense. You decouple mail reputation from your compute. If the main server IP tanks, who cares. If the relay IP tanks, you migrate just the relay. Docker volume backup, new VPS, restore, update DNS, done in an hour.
Thank you all for the many idea, I think I will try local relay VPS first, In Jakarta there is provider with clean IP for cheap, Then if fail I try the SES or Mailjet, Very helpful thread