open() throws permission error and I don't get why

[Andy Theuninck]

> I suspect that postfix is only setting the UID and the (primary) GID,
> but not the supplementary GIDs. In which case, it doesn't matter whether
> "nobody" is a member of the group.

That does seem like a good explanation. I guess I'll have to re-think
my approach a bit. sg sounds like it would give me a different group,
but multiple GIDs was really what I was looking for. Back to the
drawing board...

Thanks for the explanation though.