> On Apr 7, 2018, at 1:34 AM, J Doe <gene...@nativemethods.com> wrote: > > mmm. I just sent a test message via submission to a Gmail account and > checked the headers and the replacement works. > > According to the site [1] \s is shorthand for POSIX regular expressions. > > Perhaps the POSIX regex library compiled with Postfix now supports this ?
No "\s" is not a POSIX feature, it is however a GNU extension, so you may have a GNU regexp library, that supports "\s" (outside bracket expressions): https://www.regular-expressions.info/gnu.html -- Viktor.
