I've been having excellent results with SEE4FP (SMTP/POP3 Email Engine for Visual FoxPro), which can be found at http://www.marshallsoft.com/see4fp.htm

I ended up using it over wwIPStuff because it supports SMTP server authentication when sending mail. But even if this isn't a requirement for your project I can still recommend SEE4FP, it has useful sample programs, concise documentation, and is slightly cheaper then wwIPStuff.