How can I send an email invitation to everyone in my email list without entering each name separately?

Go to your Contacts list(Gmail). Check all your contacts list. Now click compose. Type the contents or attach the file and just click send. Your mail will be sent to all your contacts.

However, if you do the above, everyone on your contacts list will have the email addresses of everyone else on your contacts list – which doesn’t go over well with many people for privacy reasons, and also makes the email look messy because the “To” list is so long (plus the people who hit Reply All instead of just Reply… oy). What I’ve learned from some of my savvy friends is to do as above, but then cut and paste the list into the BCC field, then set the primary address to yourself – it’s neater, respects privacy of the others and all replies only come back to you.

As noted above, that recommendation is for GMail. If you use a different email service, it would help for you to indicate what operating system and email client you are working with.

@hearkat is right. You can also put a group in the BCC field and Gmail automatically expands it to all the members of the group and they won’t see who else got the email.Mail merge is also a good option where each person gets an individualized email directly to him or her.
http://www.labnol.org/software/mail-merge-with-gmail/13289/

^ what they said. My email automatically sends anything copyblasted to a contact list straight to the spam box. Many people’s emails are set up to do this also.