Just looking back, we were using the hybrid ".uucp" pseudo domain in 1995, e.g. see the contact details for the third author on this papes: https://www.researchgate.net/publication/2291331_Beyond_Hack... (not me, a colleague). For those who don't recognise this, .uucp was an unofficial "TLD" used for UUCP-based email systems accessible via an Internet relay by a dial-up modem. The relay would rewrite jlc@bmtech.uucp to bmtech!jlc, a short UUCP bang-path email address.
I used to have a book laying around - it had, or tried to have, all the email addresses in my country. Like a phonebook for email addresses. That approach didn't last long.
In 1995, I had an AIM screen name, an ICQ UIN, a Jabber thing, which we began consolidating in Pidgin, and my girlfriend was experimenting with Cu-SeeMe and some kind of “microblog” twit thing.
You could also reach us by knowing our character names on certain MUDs, which implemented a spectrum of “real time IM” to “leave a message with the bot” to “virtual room full of mailboxes which are also rooms and contain objects that are notes”.