You can sign up as an Internal User or an External Contact – one or the other, but not both. Each option has a different form.
To join ISKCON.NET you must be an ISKCON member and be at least 18 years old.
Sign up as an Internal User – Get an @iskcon.net email address and access the full range of products offered by ISKCON.NET.
Sign up as an External Contact – Have your external email address appear in the ISKCON.NET directory for the benefit of Internal Users. External Contacts cannot see the directory and cannot use ISKCON.NET products.
If you are still unsure of the difference, choose the Internal User option – the vast majority of devotees will choose this option.