As Bladepilot says - any mail program will have a way of creating a distribution list / group / mailing list with the addresses you have in the address book / contact list.
Worth checking the incoming mail for "message undeliverable" messages to ascertain problems with the email addresses being used. Could be typos, could be neglected or dead email accounts.
Also, if your mailing list is sufficiently large, it might just be possible that your ISP (or next mail relay) is seeing it as spam and dropping some of the mailing.
SD