Hi All, I have a problem where when some end-users reply to all, some of the recipients in the email chain suddenly have an extra character - a "." dot inserted in some point of the email address (the name portion or domain eg. @gm.ail.com as opposed to @gmail.com). This causes the message to bounce back with a NDR for an invalid recipient or domain. I believe this is not a client problem and the issue lies somewhere on the Exchange server's smtp service as this is happening to a few users. I have looked at the message headers of the modified emails but they do not point to where the addresses are being modified. Has anyone come across a similar situation and if so does anyone have any advice on where the email address modification is occurring and how to resolve. I am running Exchange 2K3, EE with Outlook clients. Thanks, Adam