4.4.7 NDR's on sent email - messages remain in STMP queue until expiry

We have a SBS 2003 SP2 box at office with updated Exchange. Since past few days whenever try sending any email with attachment more than 1Mb, we get a 4.4.7 delay report and a failure report after a day or two. No matter we send the mail via DNS or via our ISP, result is same.

I thought it could be the Antivirus or anti-spam software on the receiving servers but why only with attachment more than 1 MB in size? Any idea?

Hello friend, just try out these steps and see if it works for you:

• First of all contact the receiver server administrator because to me the problem seems to be their side itself.
• Also run CEICW wizard to configure the Exchange on SBS
• Other than this Symantec Antivirus Corporate Edition 9.x Internet Auto-Protect feature is not designed to run on
• Microsoft Exchange Server servers or on Microsoft Windows SMTP servers. So if you are running the same, disable it.

Thanks for your help Janos, I re-ran CEICW wizard and enabled logging wherever possible but that dint helped. By the way can you just tell me if there is any method we can use to resetting the settings without re-installation of SBS?

Usually re-running the CEICW helps us to fix many Exchange related issues. But there is no way or any wizard to reset the Exchange to default settings as its first installation.