From the actual ebuild, postgrey can only be used in inet mode; support for the socket mode would be a good addition.
Created attachment 64720 [details, diff] Ebuild diff (doc only) Diff between original ebuild and my local overlay, adding doc on socket use
Created attachment 64721 [details, diff] Unix socket support enhancement init and conf files modifications to support unix socket
Thanks for the patch, I've added this to postgrey-1.21-r1.ebuild, freshly committed to CVS. Give it a try and close this bug as fixed if it works as expected. Comment here otherwise.
Works just fine here. Marking as fixed.
Created attachment 71910 [details, diff] Better socket permissions setter Patch for postgrey.rc.new; wait until socket is effectively created and then set the perms. The previous sleep was not okay when the machine was heavily loaded, like at boot with parallel launches. This one is less randomly choosen.
Reopen for newer socket patch
Patch applied in 1.21-r2, thanks.