As an antispam measure TFN mail is set to prevent relaying of third-party mail. Users who dial-in to TFN terminal servers to pop their mail will experience no problems in sending or receiving mail. Others, who are establishing their connections via other Internet service providers will notice that they can send mail to other TFN users but they cannot send mail to non-TFN users. The solution to this problem is to specify the SMTP setting of the ISP rather than TFN's SMTP setting. All other settings can remain the same:

POP address: pop.tfn.net
SMTP address: mail.tfn.net (or use other ISP's setting)