Ok.
Here is my problem with services like that.
Many people will use it, and unfortunately, will misuse it, intentionally or not.
I did a quick search on the IP address you used to post your last message.
This IP address is listed in a few spam databases, and therefore would not be very suitable for serious business use, its "contaminated".
This is also true for plenty of telkom dial up ip addresses. when I still used telkom, I often could not send emails, because the ip address was blacklisted somewhere.
Check if your IP is listed, here:
http://www.spamhaus.org/
You will find that if you use a service that routes all traffic through one or a small set of IP addresses, or a limited set of ip addresses are assigned such as is the case with dial-up or something similar, those addresses soon get "contaminated".
This is because people are sending (email) spam, or people are infected with some virus that does it for them.
Even my sat service has problems with that. Although I have 4 private ip addresses, all my web browsing goes through a proxy, that I cannot turn off. Its also "contaminated".