I mean we are using SME server, but we didn't know how to download POP3 email from our webmail server which using redhat server. 
Please give us a clue how to set SME server so the email client (OE or thunderbird) can access webmail server using pop3. 
This is flowchart of our system : 
webmail server -> modem cable -> 
SME server -> hub switch - > client (OE or thunderbird).  
 
  