How to send emails using BCC
If you are an event organiser sending emails to many recipients it is a good idea to put the destination email addresses the BCC (Blind Carbon Copy) field, rather than the TO field. This will prevent recipients from being able to see everyone else's email address, which some people might object to.
It's very easy to do once you know how, no more difficult than sending a normal email.
Here is some links which tells you how to do it using various types of email software:
http://www.wikihow.com/Use-BCC-in-an-Email
http://email.about.com/od/emailbehindthescenes/g/bcc.htm
It's also a good idea to give your email a meaningful title in the subject line, eg "Wobbly Wheelers 27.3m - June 10th" is better than "Start Sheet". It makes it easier for the recipient to find in their mailbox and might just save you from being pestered by people who have lost the email and want you to send it again.