[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

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