Okay,
This depends on a number of things-Operations system,version of outlook, domain type.
But in general fo to control panel, mail change existing mail profile-more settings, advanced-logon network security-change it to none and it will prompt for a password.
Please reply with full os/office and network type if this doesnt apply to you.
"Sometimes I do not know but I try hard"- R.F. Haughty 1923