It was normally your email address, but you could put anything. Typically the posting news server (i.e. your own news server) was responsible for validating th

It was normally your email address, but you could put anything. Typically the posting news server (i.e. your own news server) was responsible for validating that you used your real email address. Originally there was no validation, but as spam rose validation became required. News servers required you to login, originally they were open to anyone.