YMLP - Your Mailing List Provider is an online service which offers free management of your mailing lists.
You can have up to 1,000 contacts in your list and use any one of their 30 e-mail templates to start designing your newsletters or mail shots. They offer a host of features in the free version but don’t allow tracking of who clicked on links in your e-mails.
If you need this - it is often interesting to see who is opening your e-mails and on which parts they are clicking - then go for MailChimp which limits you to 500 subscribers but offers advanced tracking and a monkey.
We have used YMLP on one of our projects and found them very simple to use, flexible and reliable. They do what they say and offer reasonable facilities. If you have a large list, then they are a good service to consider.
They also offer two paid versions at £2.65 and £3.50 per month, which probably isn’t going to break the bank if you are serious about managing your mailing lists. Each, naturally, offers a little more than the free version and includes unlimited contacts and advanced tracing.