[racbart]

Protip: If you use paid email, ask your email provider how to hide your IP while sending via SMTP. I asked mine and it turned out that they run a separate SMTP port which you can use and then your IP won't be included in message headers. This is a fairly popular provider, but I won't mention their name as they don't advertise this feature and provide it on request.

[batuhanicoz]

Why don't they advertise this?

Little "dig"ging showed who your provider is, and Google gives me no results on this feature. Also read related docs too, nothing. Wonder why.

[racbart]

Yup, my provider is quite easy to find, I don't mind. I just didn't want to make this info to be googleable with their name, to respect that they never publicly wrote about it.

No idea why they don't advertise this feature. They wrote that they only tell about it to people that are actually having a problem about it. I guess it might be easier for them or for other email-ops to handle abuse/spam issues when this header is available?