The op seems to be under the impression you can only use gmail/hotmail for inbuilt mail app, however as tim pointed out, with the right settings you should be able to use any email.
I found this:
Use the information below to configure your e-mail account, newsgroup settings and other Internet related activities.
EastLink High Speed Internet Server List:
Mail Servers-Incoming (POP3)
NS, PEI and NB pop.eastlink.ca
Access Cable E-mail pop.accesscable.net
Mail Servers-Outgoing (SMTP)
NS, PEI and NB smtp.eastlink.ca
Access Cable E-mail smtp.accesscable.net
NS, PEI and NB users.eastlink.ca
Access Cable Users users.accesscable.net
NS, PEI and NB ftp.eastlink.ca
Which should enable you to setup your east link account using the inbuilt app.