[CentOS] question for those who run mail servers

Thu May 31 13:09:30 UTC 2012
Bob Hoffman <bob at bobhoffman.com>

Not technically a centos question, but a lot of you guys seem to manage 
some large systems
and I could use some clarification on a postfix setting.*

(in postfix < 2.3 reject_unknown_client)

When I first used this there were issues with users trying to send mail 
through the server
from hotels, wireless spots, etc. This was solved by pushing up permit 

I took it out after those issues. I read many online posts from 2008 
saying too many
false positives. (though none were clear if those were incoming mail or 
from mail users)

Do you use reject_unknown_client_hostname?

Other than someone trying to access the server to send mail through it 
as a user I do
not see how this could be a bad setting and am thinking of using it.
A person sending out a mail to the server, even if in that badly set up 
hotel wireless
should be using their gmail, yahoo, own server, isp mail servers and 
should not
be directly sending from their iphone....is that correct?

or do you ignore the use of this setting still?

-thanks for any updates on the use of this setting.