Hi We would like for listserv to compare two or more lists and extract all the duplicate e-mail addresses found on these lists. What I would like to ask is can we get listserv to de-dupe across lists? I also have another question. When I send the following command to listserv: REVIEW LISTNAME SHORT NOHEADER BY COUNTRY, I receive list membership numbers by country. The question I would like to ask in relation to this is how does listserv determine where an e-mail address has come from? Is it by the .com or .co.uk, for example, or is it determined by gateway? Thank you for your help. Nevena.