The remote host is missing an update to request-tracker3.8 announced via advisory DSA 2480-2.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202480-2

It was discovered that the recent request-tracker3.8 update, DSA-2480-1, introduced a regression which caused outgoing mail to fail when running under mod_perl. Please note that if you run request-tracker3.8 under the Apache web server, you must stop and start Apache manually. The restart mechanism is not recommended, especially when using mod_perl. For the stable distribution (squeeze), this problem has been fixed in version 3.8.8-7+squeeze3. We recommend that you upgrade your request-tracker3.8 packages.