compiling postforward with current go-version v1.20 leads to the following error:
Parse error: malformed MIME header line: From foo@example.org Fri May 26 13:27:08 2023
This is not really a bug in postforward, but in go instead.
Please see golang/go#60332 for details, and the related issues golang/go#58862 golang/go#53188
Seems Envelope-From (without a seperating colon) is now considered a malformed header line
postforward works perfectly fine when compiled with go v1.19