If you have a non-profit, email may be one of the most important cost-effective tools for reaching your supporters. However, just building a list will not necessarily help your organization reach your goals. You'll need to strengthen and use the list regularly and effectively. Here's some tips on how to do that, with whatever CRM tool you're using today.
Know your audience.
You can use groups, tags or other methods to track how people came in to your CRM - be sure to track how people sign up, and what their interests are (again, you can use groups or tags for that too, to keep track of varied interests). You can usually apply them automatically based on the actions people took, or you can do queries to pull up groups of people and apply them after the fact. You can also do periodic surveys of your supporters to find out their interests.
Then make sure to use this information for targeting of your messages, so you are talking to people about things they care about, rather than things they don't.
Best practice for messages.
Make sure your emails have a point. Even though there isn't technically a cost for sending mass emails, you're asking for the time and attention of your supporters - make it worthwhile for them or they will unsubscribe or just stop paying attention to you. So make sure you're being interesting, newsworthy or relevant to their lives.
Don't waste an email by failing to have an "ask", whether it be to take an action, make a donation, or just share the news via social media. As somebody once put it, a mass email without an ask is simply mailing an unsubscribe button.
Remember you're competing against a sea of other mass email, so it helps to stand out a little. Humor can be good, as long as it doesn't rub people the wrong way. Be interesting! Try to make people feel something. If they feel nothing when reading your emails, probably soon they will stop reading altogether.
Personalize if possible.
Personalize your emails with your CRM, Dear First_Name will do better than Dear Supporter. Better yet is to know your audience well enough (back to point #1) to make sure that you're targeting people who will be interested in your content - perhaps they've taken action on that particular issue before or donated before on it. Thank people for their past work: you could segment between people who've taken action before and people who haven't -- and you could start by thanking the activists in that message segment. People like to be acknowledged and have their past efforts noticed.
You can target based on interests, or location, or past action history, or many other things.. but it is important to segment out your list so people get relevant content. Once you have your list divided up into segments, then you'll want to tailor each message so it speaks as much as possible to the concerns of those individuals. We do this a lot for fundraising: thanking people for their specific past donation in a previous year and asking them for a year-end donation, for example. Just be sure to test this kind of advanced work and make sure donation refunds etc. don't produce unexpected results in your emails like negative numbers! Also you can use A/B testing to test different subject lines, at a minimum. You can mix in custom fields to add some personalization like [[First_Name]] into the subject line - that usually tests well in our experience.
Nurture your supporters.
You can use Nurture Programs to automatically touch and manage relationships. How do you handle new supporters? You can either set autotriggered welcome series emails to welcome them in any way they might sign up for your list, or periodically run a sweep and send welcome emails to all new records. Running a sweep requires a lot more diligence than automation, but it's easy to accidentally miss an obscure landing page and some people join your list and don't get an automated welcome.
Whatever you do, be consistent about it (and plan for when you're on vacation). If new supporters don't get a good experience when they join, they may be turned off by your organization altogether, and you're missing out on a chance to work them up the ladder of engagement. PROOF that welcome series help with increasing engagement of your list.
Watch for attrition.
Over time, emails will drop from your list: people will change jobs, move away, change interests. There's nothing you can do about that, so it's a fact of life that you need to have a strategy to always be low-level building your list.
You'll need to periodically clean your email list to maintain deliverability and an engaged audience - just because people are no longer reading your emails, doesn't mean they will unsubscribe. But if you are still messaging them and they are not responding, this will hurt the email deliverability to the rest of your audience eventually.