There are various ways to make contact with your matches on the EliteSingles site, ranging from clicking 'Like' to show another member that you like their photo or comments on their profile, exchanging questions and answers to standard pre-populated '5 Questions', through to sending emails.
But, full functionality is only open to paid members. EliteSingles is very upfront about this and say that basic (free) membrship is offered as an introduction to their service to give users an idea of what the website is about.
For free, members can like and use '5 Questions', but only paid members can send and receive emails. If a member doesn't not have a paid membership, they cannot reply to a paid user that sent them a message unless they upgrade too.
EliteSingles also prioritises paid members in match results which it says is designed to ensure matches are equally as committed to finding a relationship from the site, so it is well worth becoming a paid member.