I am trying to send email from our domain, it seems that every domain we have attempted to send to since recently upgrading to Exchange 2007 from Exchange 2003 works perfect except for this one domain. As soon as I hit the send button, We get an immediate message rejection. We are able to accept emails from IBM without issue.The error we get back is:The following organization rejected your message: e5.ny.us.ibm.com.e5.ny.us.ibm.com #550 <xxxxxxxx@us.ibm.com>... cataddr: string too long ##I have researched as much as I could this mesage, and the only thing I could find is that there is some patches that should be applied on sendmail servers that it seems IBM is using. I have called directly and talked with IBM and all of thier servers have the most recent patches. I am stumped here! I have no idea where to look and it just seems odd that this is the only domain (that I am aware of) we are having an issue with. We have the correct SPF records, we are a trustedsource email domain, I have checked all the blacklist, etc. If anyone has any insight or suggestion or better yet has seen this, I will be greatly appreciated to get some assistance on this.Mark

How about you try sending an email using telnet?Just to confirm this is nothing to do with exchange, create one SMTP (IIS) domain on any of the windows XP machine by installing IIS/SMTP service and configure one SMTP domain, and smart host all the email to this domain e5.ny.us.ibm.com using dedicated SMTP connector.Arun Kumar | MCSE - 2K3 + Messaging | ITIL-F V3

Do you have ForeFront for Exchane installed in your environment? If so, check below article from Nathan to correct the problem... Mail rejection from Sendmail organisation sent via Forefront Security for Exchange http://www.mmmug.co.uk/blogs/nweb/archive/2009/03/28/26631.aspxAmit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com

Agreed with Amit and any update on this yet?Arun Kumar | MCSE - 2K3 + Messaging | ITIL-F V3

Do you have ForeFront for Exchane installed in your environment? If so, check below article from Nathan to correct the problem... Mail rejection from Sendmail organisation sent via Forefront Security for Exchange http://www.mmmug.co.uk/blogs/nweb/archive/2009/03/28/26631.aspx Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com We have Forefront Security for Exchange running on our Exchange 2007 servers and I've checked the box "Fix Bare CR or LF in Mime Headers" on both the Hub servers + rebooted them. However, we still get the NDR when sending to IBM(the sameerror as Mark in theoriginal post)Any help would be appreciated.

We are experiencing the same issue as well. Exchange 2007 SP1/RU 6 w/ Forefront SP2. Checked the boxes for "Fix Bare CR or LF in Mime Headers" and restarted the transport service on our hub servers. We are still having issues sending to IBM.Any further thoughts or recommendations?