The PTR would tend to make your system look like a generic residential connection. Therefore I would get it corrected to match the A record for that IP address. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

If it is for outbound email then it almost certainly not an issue with your server. The most likely cause is that the recipient doesn't have their DNS records configured correctly and have an MX record pointing at a server that doesn't accept inbound email, or if the MX records point to a cluster, that one of the cluster members is faulty. Depending on whether you hit the mis-configured server will depend on whether the email is sent. Not a lot you can do about it, other than alert the recipient that there is a potential issue with their email configuration. Simon. Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

Do you knoe of any other reason that this could be happening on my side. The person on the recieving side is not in the mind set that this is there probelm. I want to make sure that I have accomplished everything prior to talking with the again.

I am currently working on a clients mail system. They are server 2003 standard with MS exchange 2003 Standard. They have all the latest service packs and patches applied<o:p></o:p> Users are running either outlook 2007 or outlook 2010 client connected on the internal network to the exchange server. Under most (95%) of the cases there is no issues. There are a couple of users that will randomly get the following NDR and it seems to mostly be to the same outside domain<o:p></o:p> "Nicholas Isasi (external User) on 3/7/2012 9:36 AM You do not have permission to send to this recipient. For assistance, contact your system administrator. <MYSERVERNAME.MYDOMAINNAME.com #5.7.1 smtp;550 5.7.1 Unable to relay>"<o:p></o:p> But there are other times that they can send without an issue. <o:p></o:p> The SMTP connector in exchange 2003 under advanced is set to the proper MYSERVERNAME.MYDOMAINNAME.com The MX record and the PTR record are configure correctly. Nowhere do we have MYDOMAINNAME.local configured<o:p></o:p> We do run reverse DNS lookup on inbound messages but this issue is an outbound issueonly.<o:p></o:p> under SMTP connector access relay connections we have only the list below checked, and 2 ip address and MYDOMAINNAME.com inserted. WE also do not have the allow all computers or users authenticated check (but that should not make a difference in outbound mail.)<o:p></o:p> I have reviewed logs on the server and they all seem not to say anything of significance. Any help would be appreciate Mikek

Simon I just checked the public dns info for the external side and the mail server and PTR records do not match. This is what I get when I do the look up. Mail.DMTRANS.com - 173.12.29.66 173.12.29.66 - 173-12-29-66-philadelphia.hfc.comcastbusiness.net Can this bad PTR info be a cause?

The PTR would tend to make your system look like a generic residential connection. Therefore I would get it corrected to match the A record for that IP address. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

There isn't much you can do about it if it turns in to a finger pointing exercise. You can turn on SMTP logging and then find the connection failure and IP address, and then send that to them. However if they are using a service provider, the service provider is likely to say the same thing - not our fault. What most people will do to try and push the blame on to you is point at the NDR which hs your server listed in the mistaken belief that the server mentioned is the one with the problem - which is wrong. The server in the NDR is the one that is reporting the issue because it is unable to make the connection. Simon. Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

Simon Thanks for the response. We just got the following error back. This time saying unrecognized command The following recipient(s) could not be reached: nicholasi@dmtrans.com on 3/19/2012 10:59 AM<o:p></o:p> A critical function required for the transfer or delivery of the message was not supported by the originator of the report <nydc1.ICCLogistics.com #5.3.3 smtp;500 5.3.3 Unrecognized command> I am guessing this means there server is the originator of the report?

If that isn't your server listed in the NDR, then the email has been delivered and rejected later on. That means the issue is not with your system as the initial point of delivery has accepted it. Simon. Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.