In advanced setting did you put your user-name there?

http://nymgo.com/Nymgo-help/#faq17
Looks like link to e-series Nokia settings is non-existent so as I already said please contact Nymgo for more detailed assistance.

Also look that your phone numbers are in valid format. But then again if you are not able to even call test call then there is something wrong :|
http://nymgo.com/Nymgo-help/#faq4

Also on what internet connection you are trying to do this? Some providers block voip.

http://nymgo.com/sip-settings.php
http://nymgo.com/sip-device-Siemens.php
http://nymgo.com/sip-device-Nokia.php

.edit
I just registered there and why on earth I would pay _any_ thing to just test this service. IMO not good service at all. Just to make test call I should pay them 10$, fck that :|