There's this field in email called "bcc." Learn how to use it properly and not annoy the hell out of your friends.
"BCC" stands for "blind carbon copy" and it's a hangover from the old typewriter days. (Click here if you don't know what a typewriter is.)*
What it means: The person(s) listed in the "to" or "cc" field don't see the names/emails of anyone in the "bcc" field. In corporate america, this is great for sending secret/confidential information.
Out here in the real world, "bcc" is great when you have more than a few folks to email, i.e., more than four.
When sending out mass emails for your Tupperware party, improv show, Super Bowl party, bachelor/bachelorette party, book club, job lead, request for job leads -- you catch my drift -- send one copy to yourself, and list your myriad contacts in the "bcc" field.
Well, as is a good practice, put yourself in your reader's shoes. No one likes to get an email, open it, and then have to scroll for 2 pages past all the "to:" emails. Plus, the reader is also thinking, "Great, now all these people I don't know can contact me. I thought that's what facebook was for."
Now, once your friends pick up on this tip and start sending you clean emails, you have a responsibility as the recipient in the "bcc" field.
Do not hit "reply to all" if you're a "bcc." (You can tell you're a "bcc" if you look up at your name. It will say: "bcc: [Your Name/email].")
Why? Because the initial recipients aren't supposed to know you received this email. Secondly, mass "reply to all"s are annoying as fuck.
I once sent an email to a client of mine, recommending the services of my friend "Alex." I put "Alex" in the "bcc" field so he would know I was referring business to him. "Alex" then did a stupid thing and hit "reply to all" and addressed my client, asking for a sales meeting. Oh, I was pissed.
* I am genuinely surprised that a) typewriters are still manufactured, b) they are expensive, and c) one model is actually on backorder and not due in until Halloween of this year. Yikes!