MUDs had/have them. LPMuds in particular had ftp and later http servers built in and pioneered intermud which supported instant messaging, as well as in game mail accross servers. at least for messaging clients existed that also allowed communication with players from outside the game. message boards existed too, not sure if there were any shared across serders. i also don't know if there were bridges to smtp or irc too, would not have been hard to build though (there was apparently at least one MUD that forwarded messages from in game message boards to mailing lists, and oh, PSYCH is a messaging platform written in LPC that supports XMPP and i believe IRC too)
it is no surprise that LPC, the language LPMuds are written in served as a basis for the general purpose language Pike. there is a server written in Pike with an internal design similar to MUDs that supports not only http and ftp but also smtp, irc, xmpp and other protocols. i use that for my own websites.