We had problems sending email to AOL and several others, and it came up that we do not have a PTR record. We contacted the agency that hosts our DNS and were told that "Some people prefer not to have them to provide a slightly increased level of security." What are the perceived security risks of having a PTR record? Pros and cons?
Thanks,
/ljb
-----Original Message-----
From: Daniel Donnelly [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, June 06, 2001 3:36 PM
To: [EMAIL PROTECTED]
Subject: Re: [IMail Forum] List Server Errors
Actually the suggestion you got, was on the money. Here is what I see in DNS for the domain in your email address. The reason you can send to most addresses is because most server do not do the PTR check, but the 'big guys', AOL and the like (typically those using SendMail servers, I have found), often do. Bet if you look more closely, you cannot send 'normal' mail to the problem addresses/domains.
800mcmahan.com.
nameserver = CBRU.BR.NS.ELS-GMS.ATT.NET.
nameserver = CMTU.MT.NS.ELS-GMS.ATT.NET.
nameserver = MSC1.800mcmahan.com.
1, mail.800mcmahan.com.
mail.800mcmahan.com.
12.38.72.11
11.72.38.12.in-addr.arpa.
alias = 11.0/25.72.38.12.in-addr.arpa. 11.0/25.72.38.12.in-addr.arpa.
host = newmail.800mcmahan.com.0/25.72.38.12.in-addr.arpa.
** this is not a good record!! It should look come back like this:
host = newmail.800mcmahan.com.
But notice that the hostnames are different (mail and newmail)!
** and I'm not sure about that alias, either! Normally an alias (CNAME) shows just another 'hostname'. I suspect these 2 DNS problems are related, but only a guess **
Daniel Donnelly ________________________________________________________
----- Original Message -----
From: "John M. Miller" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, June 06, 2001 2:39 PM
Subject: [IMail Forum] List Server Errors
> After having switched to IMail within the last month we used the List
> Server for the first time the other day. Unfortunately we got a very
> high number of our messages sent through the list server rejected by
> an assortment of receiving post offices. The weird thing is that we
> have absolutely no problems sending "normal" emails and are sending
> them to many of the same post offices and recipients.
>
> It was suggested we might have a problem with our PTR record in the
> DNS but we believe that if we had a problem with it we would have
> trouble with the normal emails. Has anyone run into these kind of
> problems?
>
> Thanks,
>
> --John
>
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