Server 2003 Standard Edition
I use WebDAV to send e-mails (receipt from webshop for example) to users.
The sent messages are ALMOST always being rejected by the remote server, eg:
Message delivery to the host 'xx.xx.xx.xx' failed while delivering to the remote domain 'somedomain.com' for the following reason: The connection was dropped by the remote host.
When I forward the same message to the same adress using OWA, the message is being delivered.
I have tested to send to my own gMail account, and it works most of the times, but sometimes the same message can be rejected.
The message appears in "sent"-folder and appears in the Exchange queue.
I use a smarthost normally, but have tried to switch to DNS, with no luck.