I live in the USA and I have a small forum with just under 100 members. When they registered I never offered a newsletter check in option. Can I send them a mass e-mail with site updates and changes or is this illegal? What would I need to do to make it legal if it isn't?
If you aren't trying to sell them anything you shouldn't run into any problems. If you are going to try and sell them something (even if it is related to your site), you can still email them. Opt-in is not required in the US like it is in the EU. Just make sure that you follow the Can-Spam Act compliance guide and have a system in place where you can opt them out if they request it.
What about adding an opt out in the e-mail? Is that required? I don't know an easy way to do that with a Joomla CMS. Is an Opt-out not needed either?
All requirements for Can-Spam Act compliance are listed in the PDF I provided a link to. Just spend a few minutes reading through it to make sure you are going about things legally. If you don't have the technical skills to set up an automatic opt-out, don't want to use a newsletter mailing service, and aren't going to hire someone to script a system for you, you can go the old-fashioned route. Set up a second email, something like , and give them instruction to just forward the email to that address to stop receiving mailings from you. Just check that email account once a week (you have 10 business days to honor an opt-out request) and remove any email addresses that sent an email to your opt-out email address.
Amazing advice, Mhovingh. I completely agree with everything you said. The OP could also place a pop up for members to sign up from for members.. or even send the newsletter to the private message box on the forum.