Okokuqala, u-Alice ubhala umyalezo oya kuBob kwi-program yakhe ye-email. Iprogram yakhe ye-e-mail iyavuma ukuba awubhale umyalezo wakhe aze awubeke ndawonye nolunye ulwazi, njengedilesi ye-email yakhe, idilesi yomntu ambhalelayo, ixesha awuthumele ngalo umyalezo wakhe, njalo njalo. Iyakuthi ke xa sele igqibile i-program ye-e-mail kaAlice iwuthumele loo myalezo kwi-central computer ebizwa ngokuba yi-mail server (okanye i-Mail Transfer Agent) isebenzisa inxalenye yemithetho ebizwa ngokuba yi-Simple Mail Transfer Protocol.