Does postal still use outdated rails? That's the biggest issue I have with this project as a exposed web service and mail server is for me high risk especially with outdated software.

They seem to be on 7.2, which will get security patches until August this year:

https://github.com/postalserver/postal/blob/8ef89606bc34146f...

https://rubyonrails.org/maintenance

Not great, but better than 6.x.

The links shows: gem "rails", "= 7.1.5.2"

I don't know rails well, but that sounds like 7.1 (that is unsupported) and not 7.2?

Ah, my bad. Wishful thinking going from GitHub to rails site.

Rails minor versions are a bit odd imnho - but you're right 7.1 isn't under support anymore.