I have a server running Windows Server 2003 and Exchange 2003. When a user sends email to a specific domain, it will go through instantaneously except if it has an attachment. The domain the email is being sent to says the email is not reaching their servers and message tracking confirms this. Is my firewall blocking it or is it something to do with exchange? The attachments are well within the size limits (att size 2mb and limit is set to 5mb).
When the server is restarted, users receive NDRs for emails they sent a long time ago but those messages were not in any of the queues. VEry strange indeed.