 The mailer would initially answer the phone and, if necessary, deal with incoming mail via FidoNet transfer protocols.If the mailer answered the phone and a human caller was detected rather than other mailer software, the mailer would exit, and pass control to the BBS software, which would then initialise for interaction with the user.When outgoing mail was waiting on the local system, the mailer software would attempt to send it from time to time by dialing and connecting to other systems who would accept and route the mail further.