Minimum Requirements
The most important minimum requirement for signing up with vPSI Online is that you must be able to receive emails from vPSIOnline.com and vPSIGroup.com.

Email accounts that are not free work best whereas email accounts from Hotmail, Yahoo, or GMail have the most issues with spam filters. Unfortunately vPSI Online is powerless to make changes to your email filtering. Email host are usually receptive to requests for unblocking emails so if you suspect that vPSI Online emails are being blocked, please contact support for your email provider.

Besides being blocked by your email service, vPSI Online emails may also be treated as spam by your email client or firewall software running on your machine. Adding vPSIOnline.com to your software's Safe Sender list may help. You'll need to consult the manual for your software to get this done. Here is what Outlook 2007 looks like when configuring Safe Senders...