Hello, in our Exchange on our SBS 2003 we sometimes have the problem, that certain emails are delivered to the regarding customer, but the mail stay in the queue with delivery error. Meaning, Here is a entry in "Server" - "Servername" - "Queue" for the domain name of the customer. Searching for emails to the customer brings up one that is repeated serveral times (160+). The customer complains, that he gets the message every few minutes. We forward all mail from Exchange to an IIS SMTP in the local network. This only occures every few weeks, but how can that be? Regards, Uwe

Hi, What client do you use to send email? Please post the detail information about NDR.Also please use messge tracking to trace where the message will be hung.Please post the tracking here.Besides,I'd like to know if the issue only occur to certain customer,is it a outside user?contact?inside user?Regards,Xiu

hi, the clients are different. Outlook, or MS CRM are the most common. This issue does not occur very often, but it does occur. It occurs on single emails only. meaning i can send another mail to the same contact and it goes through well. Our Exchange uses a smarthost to send the mails to the IIS SMTP on another local server. This IIS SMTP forwards the emails to a "bitdefender for mail servers" on the same machine. Is it possible that the bitdefender does not sign the reception of the mail, so that exchange is trying again? Regards, uwe