[CentOS] USB install annoyances
John R Pierce
pierce at hogranch.com
Mon Jan 9 21:37:22 UTC 2012
On 01/09/12 1:30 PM, Ljubomir Ljubojevic wrote:
> I own my own domain/server/subnet. My WISP customers can only send mail
> via my server, with all the prevention's I could think of. I have never
> been hit with this (but I do have small customer base), but I have had
> regular domains (like one local Bank!!!) blocked to deliver to my server
> because they do not have proper FQDN.
I too run a few mail servers... none of my servers will accept incoming
email from a host that doesn't have a reverse DNS that when looked up
returns the original IP (eg, IP -> reverse -> forward -> IP... note this
doesn't have to match the HELO name). I also check that the 'from'
domain name has an A or MX record. This sort of thing has been
standard practice for email servers for at least 15 years. The way I
figure it, if someone can't get the DNS right, they shouldn't be running
a email server at all.
john r pierce N 37, W 122
santa cruz ca mid-left coast
More information about the CentOS