Hi, We are having Exchange 2003 in the mixed mode environment. If we send a mail to an ID having special characters (Eg: abc.def@xxxxxxxxxxxxx), they are not receiving it. Same response is there if they send a mail to our mail IDs. Your suggestions are highly appreciated. Thanks Mahadevan Confidentiality Statement: This message is intended only for the individual or entity to which it is addressed. It may contain privileged, confidential information which is exempt from disclosure under applicable laws. If you are not the intended recipient, please note that you are strictly prohibited from disseminating or distributing this information (other than to the intended recipient) or copying this information. If you have received this communication in error, please notify us immediately by return email.