I had a problem for a few months collecting email from my ISP's mail server. My email program was Eudora on an Win98 machine with DSL going into the e-smith box. I could send mail but not receive unless I used my old dial-up connection on my PC. I also had to use dial-up to FTP out and to collect info from newsgroups. After much advice and head scratching, I solved it myself by going into each Windows program and changing some settings. In Eudora, I had to change the name of the mail server from mail.myisp.net to the IP address which is a number string that your ISP can tell you, or you can get it yourself with the ping command at the MS-DOS prompt in Windows. C:>ping mail.myisp.net This command will return the IP address (among other things) that will look something like this 206.56.172.1 That's what worked for me. If you access other servers at you ISP with other software, you'll have to change those settings also.
HTH
Rod