If you have a now quite ancient Nokia Symbian phone such as the E51, you can no longer use “Mail for Exchange” to access your contacts, calendars etc with Gmail (unless you pay); but you still can as of March 2015 with Outlook.com and Hotmail.com addresses.
If you try to install Mail for Exchange now, you’ll get a certificate error, so set your clock on the phone back to somewhere around 2010-2012. Then it should install OK.
On the phone just enter the server as outlook.office365.com and it seems able to work out the exchange server by itself.
I’m not sure if linking Outlook to Google from within outlook.com actually works. If not, to move from Google to Outlook export your contacts from Google then import them to Outlook.com.