Why BCC is Important: A Public Service Announcement
The Problem

When you send an email to multiple people and you put all their email addresses in the 'To' or 'CC' (Carbon Copy) field, every person who receives your email will be able to see the email addresses of everyone else you sent it to.

This is rude, plain and simple. You wouldn't give out your friends and family's phone numbers to a bunch of other people without their permission. Giving out their email addresses is the same.

The Solution

Thankfully, email providers and clients have a handy feature to stop this happening. Instead of putting your list of email addresses under 'To' or 'CC', put them under 'BCC'. BCC means Blind Carbon Copy.

When you put your list of email addresses under BCC, it will go to each one of those email addresses, but they won't see the names/addresses of everyone else it's been sent to.

Some email clients won't let you send an email with nothing in the 'To' field. This is also easy to get around. Put your own email address under 'To' and everyone else's under 'BCC'. Then the only email addresses that each recipient sees will be their own and yours.

A Quick Note on Forwarding

The solution above should also be used when forwarding emails. However I'd really recommend against that. Forwards are never as funny, original or interesting as you think they are (see here).

Also, before you forward on that 'really really important piece of information', please for the love of all that is good, first check Snopes (the Urban Legends Reference Pages) to make sure it's not a hoax. So far, every single email forward I've had warning me about 'some really important thing that I must be aware of', has been disproven in seconds with a quick search at Snopes.

I'm not saying don't forward emails at all. If it's something relevant to the person you're sending it to - for example something about their favourite band, or something you think they personally should see, go right ahead. But please, please be discerning. Don't send every cute kitty photo or hilarious joke to every single person in your address book. Have some class.

So from now on, when you send an email (or forward) to multiple email addresses, please be courteous by using BCC instead of To or CC. Giving out people's email addresses in forwards or mass emails is plain rude.

Thanks for your time, folks.