i have a problem and it's not been solved yet. i installed Windows SBS 2003 Server forone of thebranches of my company (and it's also the Exchange mail server). we have 30 winXP and 9 MAC workstations over there. my problem is with the Exchange server (it's the same SBS 2003 server), i already configured all the workstations for the POP3 and the SMTP server, and all working perfectly (sending and reseiving inside and outside). but i have only two desctops (windows XP SP2 with MS-office XP) that are getting administrator's messages of not finding the recipients email addresses when sending (Ex. @hotmail.com, @yahoo.com). but i have been shocked when i tried to send from the same accounts through the OWA, the emails was successfully sent, and i didn't get administrator's email, and i found the emails on one of my accounts of HOTMAIL and YAHOO. please someone tell me what to do, am not familiar with this broblem and am gonna be fired if i didn't fine a solution. Bashar

Hi, Problem is not with the exchange server Problem is the configuration on the 2 workstations. Why do you configure the workstations to run pop3? It would be much better for you if you configure the workstations to run MAPI (standard Outlook to exchange communication). If you really must run POP3 you need to post the NDR received when trying to send external mails from these workstations. Leif

hey Leif thanks for your help, am going to try it once i get there. and i hope it works. there're few things i forgot to mention before, the network is only workgroup (not a DOMAIN). and i connected all the clients on outlook for POP3 and SMTP to direct both to the Exchange server IP Address. and all other clients are working pretty good. anyways thanks again for your help.