Email might just be the best way to connect with people. After all, it offers a wider reach and more personal interactions than social media. But it’s not enough simply to build an email list. While you focus on adding subscribers, you may be overlooking how your list declines in quality day by day. This deterioration could transform your most effective outreach into something that goes completely unseen.

Email marketing has the highest ROI at $42 for every dollar spent, not to mention the benefits of being instant and versatile. Want to run a last-minute promotion? Have a message you need to get out in a hurry? Need to reach a segmented portion of your list? Email makes all of this possible.

Email lists reach people where they’re already looking: their inbox. Researchers at the University of British Columbia found people check their email at least 15 times a day. However, they rarely check spam folders. Meaning if you miss the inbox, your message might as well have gone unsent.

“That’s why taking good care of your list is vital to your email marketing. And when you consider how easy it is, it makes no sense to take any risks,” says ZeroBounce COO Brian Minick.

Here are five easy ways to improve your email list within hours, increasing your inbox placement and ROI.

Cull Invalid Contacts

Imagine you’re mailing out a stack of letters. Before you address the envelopes and stick on the stamps, wouldn’t you want to know if the addresses are good?

People also change email addresses. They finally ditch that Yahoo address. Maybe a workplace or school account becomes obsolete. Yet, it feels like far less of a big deal to send an email newsletter without updating your contacts. You may think that because the majority of your email addresses aren’t bouncing, everything’s fine. Indeed, many marketers would agree with you.

You’re all mistaken, because damage is definitely being done. The truth is that sending emails to invalid contacts harms your sender score. Email service providers (ESPs) use this score to determine who is a reputable sender and who is a spammer. Your sender score and reputation have a great impact on the deliverability of your email campaigns. Thus those bounced emails can come back to hurt you.

So emailing invalid contacts drives down engagement. It also costs you money. Most email delivery services charge based on the size of your list. Quite simply, your email list requires the same care as one for snail mail.

Kick Out the Complainers

Spam complaints negatively affect deliverability, so make sure everyone on your email list wants to be there. This means buying lists is out of the question. You should also use double opt-in to confirm the subscriber really wants your messages. (After they sign up, a simple email with a link must be clicked as proof of intent.)

Even with the double opt-in, you may still have problems. Some people make a habit out of marking emails as spam, even emails they sign up to receive. Whether they act out of malice or carelessness, your reputation can take a hit.

Dump Disposable Email Addresses

Some sites assign disposable email addresses that self-destruct after a while. (They’re called burner or temporary emails.) People may sign up using disposable email addresses to take advantage of an offer, but avoid sharing their real email address. Thus they receive their promotional item and soon after their temporary account closes.

While customers with disposable email addresses may move on, you get a lasting problem. As these disposable accounts become invalid, they begin to bounce your messages, damaging your deliverability. Make sure to remove them periodically.

Validate Your List

Here’s a way to improve your list that is imperative and easy. Locate a trustworthy, well-reviewed email validation service. Then upload your list to validate it in bulk. Now you can eliminate the emails discussed earlier, as well as catch-all emails, role-based emails, and spam traps. Will this make your list smaller?

Probably, but the accounts you lose are ones you’re better off without. As ZeroBounce COO Brian Minick puts it, “Keeping a list of engaged, high-quality email addresses only means greater deliverability and ensures that you’re sending your campaigns to interested people. Who wants to talk to a crowd of the half-hearted or bored?”

Or, for that matter, the nonexistent.

Prevent Bad Signups With an Email Validation API

You can make your regular list cleanings a little easier by preventing unwanted additions in the first place. Use an email validation application programming interface (API) to check newly signed up addresses in real-time. It’s a great way to keep damaging inclusions from occurring. A good email verification service should provide the code you need to set up this essential step.

A successful email list is a uniquely effective way to connect with your intended audience. A poorly maintained one may go unseen, as it skips inboxes and winds up stuck in spam. So before you send out that next perfectly crafted email, take a moment to follow these simple steps. That way, you can ensure its intended recipients actually receive it.