Chris: A number of IP address related issues can cause this, particularly if the mail server has been moved to another subnet or moved behind a router.
Could be: 1.. No or incorrect PTR record at the ISP level pointing back to your mail server domain 2.. The PTR record is identifying an incorrect (internet) domain name for your server 3.. Your DNS Host is listening on incorrect IP addresses (maybe they changed and the Listen IP address was not also changed) 4.. Your relay settings may need to change include the IP subnet where the sender is located - this can happen if the mail server is moved behind a router onto an internal address compared with being on a public IP address 5.. The Domain Name Server address in the I-Mail SMTP Service is wrong First go to www.dnsstuff.com and enter the IP address of the mail server, or the router in front of it in the Reverse DNS Lookup, click the button and check the results. The next to last line should say Answer.... and should list the A records and addresses from the DNS server. That'll confirm if the ISP PTR record is correct, and if your DNS is pointing back to the right IP address - if not you'll get an error. Make sure the ISP has the right domain name set in the PTR record. Then give some thought if you need to be allowing Relay for some address ranges, like if the sender who has problems is behind a router, give the IP address for the outside of the router, and the appropriate Subnet Mask (be careful to give the real IP address for the beginning of a block, which should be an even number, then make sure the subnet mask is correct. Then do a bit of experimenting. I would suggest you get two computers on different networks and e-mail between the two to check out the results I just went thru all this when I changed my Mail server from one TimeWarner account to another. It was on a public IP address, but is now behind a router and has an internal address. Cheers Ted Daniels ----- Original Message ----- From: "Chris Ulrich" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Thursday, March 15, 2007 3:51 PM Subject: Re: [IMail Forum] Strange Problem occurring with Code 553 > The problem is, this is not spam. > > This is a legitimate client sending an email to someone and getting > this as a bounce-back. > > > > At 01:39 PM 3/15/2007, you wrote: > >We've seen a lot of forging spam lately with headers forged like > > > >Received from xxx.xxx.xxx.xxx (HELO mail.example.com) > > > >These have typically used an IP that we have associated with a mail server > >hostname, but are not currently using. Unfortunately the receiving server > >is not using REVDNS or they would have seen it wasn't actually sent from > >that IP. > > > >Perhaps you're seeing a problem resulting from something similar? > > > >Darin. > > > > > >----- Original Message ----- > >From: "Christopher Checca" <[EMAIL PROTECTED]> > >To: <[email protected]> > >Sent: Thursday, March 15, 2007 11:28 AM > >Subject: RE: [IMail Forum] Strange Problem occurring with Code 553 > > > > > >I'm having the same problem with a godaddy hosted account we send to ... > >they claim we are using an IP address that we don't use and have us blocked. > >No answer yet ... we've been working with them for over a month now. > > > >Christopher Checca > >Packard Transport, Inc. > >IT Department > >24021 South Municipal Dr > >PO Box 380 > >Channahon, IL. 60410 > >815 467 9260 > >815 467 6939 Fax > >[EMAIL PROTECTED] > >www.packardtransport.com > > > >-----Original Message----- > >From: [EMAIL PROTECTED] > >[mailto:[EMAIL PROTECTED] On Behalf Of Chris Ulrich > >Sent: Thursday, March 15, 2007 11:18 AM > >To: [email protected] > >Subject: [IMail Forum] Strange Problem occurring with Code 553 > > > >For the last week we've had a big problem with complaints that some > >messages are being returned indicating: > > > >553 Bogus Helo italy101. < http://unblock.secureserver.net/?ip=69.74.100.2 > > > > > > >Our mail server isn't 69.74.100.2, it is 69.74.100.88 > > > >We've gone in and tightened up MS SMTP service (which one client was > >using for a form-mail like app) > >which *may* have been NAT'd to that IP address (still not sure). > > > >If I telnet to that .2 address on ports 25 or 110 nothing appears to be > >there > > > >Any suggestions on why this might be occuring, what it means and what > >I should look at to address it? > > > >Thanks !!! > > > >To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html > >List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ > >Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ > > > > > >To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html > >List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ > >Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ > > > >To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html > >List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ > >Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ > > To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html > List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ > Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ >
