The Newsletter MOD is a great way to go, just remember that down the road when your site does get bigger, and it should

, that your web host may have a certain amount of time that it allows for you to use its shared resources at any one given time. I assuming that you are presently on a shared hosting account.
On one site I worked on, the web host only let a script of code run for two minutes before it timed out which meant that only the members at the beginning of the mailing list got the mail.
Don't be alarmed though!
Right now, you should be very OK! It's just when you get into the hundreds, or hopefully, the thousands, of subscribers that what I mentioned "might" become an issue depending on your hosting plan.
If it does happen, you might want to check with your host to see what its allowances are and if it can up them for you. By then, you may be on a more robust hosting plan. It may never be an issue for your site, but just keep it in the back of your mind if your mailing list does time out ... that a script timeout with your host may be the problem instead of the code in the Newsletter MOD.
Good luck!
Etymon