Using his email address to log in would be 'account sharing' and is 'against the rules'. If you're simply talking about contacting to discuss things then swapping e-mail addresses is a perfectly valid system. Many players have each others contact details, either the email they use for logging in or a regular one. Players also use systems like TeamSpeak to contact each other via voice.
I don't know of a system whereby EA act as intermediaries other than in-game contact via different worlds or the messaging system on here (which only works if the other player logs in here).