POP3 and IMAP are not enabled by default in Exchange. If your administrator enabled them, in most configurations they would run on the same server(s) as OWA (webmail), so you can try that and see what happens. Of course, you could also try asking your IT department.
MeEtc has a good suggestion too. Knowing him, he probably means Blackberry -- however, iPhone and anything running Windows Mobile support Exchange ActiveSync (OMA), which is installed along with and at the same place as OWA, so you almost certainly have that.
