Computer Centre (CC) never sends email for getting user information. Kindly discard such e-mails purported to be originated by CC to gather your LDAP username and password or any other personal information. This may be a phishing mail. Know more...
New entrants into the LDAP system must accept the online IT Agreement before attempting NETMON/GPO/NEWS access (click here to sign it). Please be while signing the policy.
IMAP and IMAPS based access to the MAILBOXes available at on port 143 and 993 respectively.
Alternate methods to access WEBMAIL services:  (a) IMP  (b) Ilohamail  (c) Hastymail
Some basic documentation about IITB WEBMAIL :