I have a windows 2000 SMTP service that forwards my mail to an Exchange 5.5 server. Sometimes it fails to deliver HTML messages to the exchange server. This message is recorded in the eventlog. "Message delivery to the remote domain 'xxx.co.uk' failed for the following reason: Unable to successfully connect to the remote server." It then delivers an NDR that contains the original message in it? Any thoughts? Cheers, John Burridge