I have single Exchange server 2003 STD edition with SP2 running on Windows server 2003 STD edition.Problem: Not able to send mails when configured account as POP3 from outside world in Outlook/Outlook express/mobile device other than windows mobile.Description: I have single Exchange 2003 STD edition with SP2 running on Windows Server 2003 STD edition wih SP2. I enabled POP3 service on exchange, opened POP3 port in my Cisco PIX. Configured my e-mail on my mobile device as POP3 service. I sucessfuly received all e-mails. But failed sending e-mail to my company ID or even to any 3rd party ID like GMAIL etc.I did search over Google. Also went through articles submitted here. But no similar thread I found to get resolution on my problem.What could be the problem?I am able to receive mails but not able to send when configured my server as POP3 server from outside world.My exchange server is not smart host yet. [ I found 1 TechNet article which describes about enabling Exchange server as SMART HOST.]I am little confused.If I enable my SMTP virtual server as SMART HOST, I am going to put internal domain name in it or I am going to put the registered domain name which I use as my e-mail ID ? Like > xyz@mycompany.com In my case I'll have to add mycompany.com as SMART host ?And yes 1 more confusion as never configured POP3. Is it required to put POP3 wording format while configuring exchange as a smart host or configuring my exchange account in Outlook/Outlook express as POP3 server ? Like we do for GMAIL , we add POP3 or POP prefix. Confused !! http://technet.microsoft.com/en-us/l...EXCHG.65).aspx > Just found this link. Adding 1 more SMTP connector and making my Exchange smart host will solve the problem ? Any help? Regards,Amey.

Hi, Remember that POP3 is only for receiving mails - in order to send you need SMTP. So you need to make sure that the clients can access the SMTP service and that you have allowed authenticated users to relay. Be carefull with the SMTP settings - if you make a mistake here spammers will know it within minutes. Leif