Another interesting thing. If I do an NSLookup (set type=mx) on their email domain it returns an IP address for the mail exchanger. If I do this on any other domain it gives me an FQDN and then gives the IP of the FQDN later on in the information returned. I tried to do a reverse lookup on their IP and it does not resolve. They can send to us and I can send to them from my Hotmail account. Would this be any reason that I can not send to them from my Exchange server? As I am sure you can guess I am pretty new to DNS so please don't laugh too hard at they way I tried to describe the NSLookup. : )
-----Original Message----- From: Simon Taylor [mailto:[EMAIL PROTECTED]] Sent: Thursday, October 25, 2001 11:20 AM To: MS-Exchange Admin Issues Subject: RE: Relay Hey John To my knowledge you cannot do this in Exchange 5.5, no idea about 2000. I use Sendmail Switch for my production Mail relays and they can be configured to do so. You may want to telnet to the smtp server in question and give it an HELO and it will give you the relay version you are dealing with. Cheers Simon -----Original Message----- From: Montgomery, John [mailto:[EMAIL PROTECTED]] Sent: 25 October 2001 16:10 To: MS-Exchange Admin Issues Subject: RE: Relay That wasn't what I was asking, but that does answer another question I had so thank you. : ) How can you tell if the IMS on Exchange is setup to perform reverse DNS lookups on inbound email, or does it just automatically do that? Thanks, John -----Original Message----- From: Simon Taylor [mailto:[EMAIL PROTECTED]] Sent: Thursday, October 25, 2001 10:47 AM To: MS-Exchange Admin Issues Subject: RE: Relay Do this Run nslookup first on your exchange machine (or whatever you call your mail system.) Then run nslookup again on the ip address it give you for that system and if it resolves then you are indeed setup for reverse lookups. You may want to run nslookup off an external dns server as internally it may work, but not external. ------------ H:\>nslookup Default Server: ns5.domain.com Address: 192.168.1.32 > server ns1.bt.net Default Server: ns1.bt.net Address: 194.72.6.52 > mail.domain.com Server: ns1.bt.net Address: 194.72.6.52 Name: mail.domain.com Address: xxx.xxx.xxx.xxx Aliases: imap.domain.com > xxx.xxx.xxx.xxx Server: ns1.bt.net Address: 194.72.6.52 Name: mail.domain.com Address: xxx.xxx.xxx.xxx Aliases: imap.domain.com > --------------- Let me know if you need anything else... Cheers Simon -----Original Message----- From: Montgomery, John [mailto:[EMAIL PROTECTED]] Sent: 25 October 2001 15:13 To: MS-Exchange Admin Issues Subject: RE: Relay How do you look to see if reverse DNS lookup is setup? I realize that this would be on their side, but I would like to know for myself. I have been looking but can not seem to find it. Thanks, John -----Original Message----- From: Simon Taylor [mailto:[EMAIL PROTECTED]] Sent: Thursday, October 25, 2001 5:41 AM To: MS-Exchange Admin Issues Subject: RE: Relay I have in the past had relays refuse when they could not perform a reverse dns lookup on the address I was coming from - I would check their end if you can email to other domains just fine.. Cheers Simon -----Original Message----- From: Montgomery, John [mailto:[EMAIL PROTECTED]] Sent: 24 October 2001 23:19 To: MS-Exchange Admin Issues Subject: RE: Relay I did this and using SAlive made an SMTP connection to the IP address. It connected just fine. What seems strange is that it is coming from our IMS saying MSEXCH:IMS:HoneyBaked:Site:Server 3550 (000B09AA) 550 5.7.1 Unable to relay for [EMAIL PROTECTED] To test the GroupShield scenario I stopped GroupShield and tried it again. It still failed so I am assuming that this is not the problem. -----Original Message----- From: Benjamin Zachary [mailto:[EMAIL PROTECTED]] Sent: Wednesday, October 24, 2001 4:52 PM To: MS-Exchange Admin Issues Subject: RE: Relay You may want to nslookup on the MX record for DNS and make sure its pointing to the correct location. NSLOOKUP -Q=MX DOMAIN.COM -----Original Message----- From: Montgomery, John [mailto:[EMAIL PROTECTED]] Sent: Wednesday, October 24, 2001 3:30 PM To: MS-Exchange Admin Issues Subject: Relay We are having a strange problem. We send to a particular domain and get an NDR back from our server saying that relaying is prohibited. This same domain can send to us and we can send to other domains just fine. We were able to send to them before. Has anyone else seen anything like this? We have recently upgraded GroupShield to 4.5. I called their tech support to see if this was anything that they may know about, but they said that it is not. I have tried searching Microsoft but could not find anything. Exchange 5.5 SP4 Thanks, John Montgomery Information Technology LAN Administrator HoneyBaked Ham List Charter and FAQ at: http://www.sunbelt-software.com/exchange_list_charter.htm List Charter and FAQ at: http://www.sunbelt-software.com/exchange_list_charter.htm List Charter and FAQ at: http://www.sunbelt-software.com/exchange_list_charter.htm List Charter and FAQ at: http://www.sunbelt-software.com/exchange_list_charter.htm List Charter and FAQ at: http://www.sunbelt-software.com/exchange_list_charter.htm List Charter and FAQ at: http://www.sunbelt-software.com/exchange_list_charter.htm List Charter and FAQ at: http://www.sunbelt-software.com/exchange_list_charter.htm List Charter and FAQ at: http://www.sunbelt-software.com/exchange_list_charter.htm List Charter and FAQ at: http://www.sunbelt-software.com/exchange_list_charter.htm
