Your aim when applying for a job, or sending over your CV as a speculative application, is to get the recruiter's interest and to make them want to arrange an interview with you. If they do decide that they want to interview, or would like to discuss your application further, this requires knowing your contact details. Sometimes CVs sent in through jobs boards have no contact details on at all, so it makes it very hard to contact the candidate with any further questions.

This is especially important if you are applying direct. I have once received a CV through the post with no contact details on - I'm not entirely sure how the candidate expected me to contact them if I was interested in speaking to them further! Contact details should be one of the first things on your CV, after your name of course. 

It is also useful to include a contact telephone number as well as your email address, as some recruiters/hiring managers will prefer to discuss roles over the phone and others will prefer to speak via email. Email addresses should also be professional - just your name if possible. Although funny, it doesn't come across well to a recruiter if your email address is something like 'liamluvsjade4eva@hotmail.com' especially when applying for a role in a professional services firm. It takes less than 5 minutes to set up a new email address that looks professional, and it is free!