There are quite a few ways that you can send mass mail to people nowadays. Out of all these ways, we have only found two real ways that work well and reliably. Let's start with the ways that do not work:
BAD: Composed message with several BCC (Blind Carbon Copy) entries
The main problem with this is that spam blocking applications can easily identify these messages as spam. So although you might be able to easily send out a single message that must be copied to several people, it more often than not, will end up in most of the recipients spam boxes. The exception is perhaps if you keep it down to 20 or so recipients and only one single e-mail. But that isn't really "bulk e-mail".
Another downside is the recipient cannot get a customized message. You, for example, can't write "Hey Bob" at the top, because not only Bob is going to get the e-mail.
BAD: Your own script
Scripts often send out lots of e-mail as fast as possible. Without knowing advanced programming techniques and building a queue that manages the mail, you are more likely going to get picked up as a spammer. There is nothing that spam blockers pick up easier than thousands of e-mails with exactly the same copy. Unless you know how to throttle e-mail sending or do it in batches, your e-mail is more than likely not going to arrive at the intended recipients inbox.
Now that you know how not to send bulk e-mail, we recommend the following two good ways to send bulk e-mail correctly:
GOOD: Using an Online Service
There are tons of services who specialize in sending e-mail to multiple recipients. The two most popular we know is MailChimp.com and Aweber.com . Both of these offer FREE trials, so they are worth checking out before considering spending money on them.
The downside is, should you choose to make use of a service like this, it will most likely cost you quite a bit of cash each month.
GOOD: Use an advanced script
There are advanced solutions like PHPList available that can help you send e-mail correctly. It can automatically batch files, limit how many are sent to a single service provider at a time, give you statistics on deliveries and many other great features.