When was the last time you looked at your subscriber list, and I mean really looked at it? Do you know who your real audience is? What's your bounce rate?

It's easy to set your subscriber list and forget it so you can focus on the content — because content is, after all, king. But the foundation of every successful email campaign is a well-maintained subscriber list. A clean email list provides more accurate statistics and improves deliverability rates.

The best part is that it cleaning up your list doesn't take long at all. Here are two things to check for when cleaning your email list.

1. Hard bounces

A quick way to improve your deliverability rates is to weed out the hard bounces. These occur in three ways:

  • when your recipient's address was incorrectly typed (abc@mgail.com)
  • when the domain name doesn't exist (dfksd@dfjdfd.com)
  • when the recipient is an unknown user (deleted email address)

The number of hard bounces you get per mailing helps determine your sender reputation. Email clients look at this to determine if your email will either land in your recipient's inbox or spam folder.

A good email analytics report will include a list of bounces per mailing. Double-check these addresses for obvious typos. Also, check your email bounceback messages for any change-of-address emails and update those accordingly.

People are usually not aware that they are bouncing email until someone tells them, so email them and let them know. For anyone who doesn't respond, you're likely dealing with a dead email address remove those. Most email service providers do this for you, but not all do, so make sure any email that hard bounces is removed from your list.

2. Graymail

How many times have you given your email address while checking out online or at expos for that snazzy stress ball only to be sent emails that you don't open and can't be bothered to unsubscribe from? You, my friend, are graymail.

This type of a subscriber is a person who has opted into receiving email, but who doesn't really want it. Anyone who hasn't engaged with your emails in the last 6-12 months should be grouped into this category.

Don't get rid of these addresses just yet!

One way to reel the graymailers back in is to send re-engagement emails to this group. Don't take this step lightly. This may be your last-ditch effort to win them back, so pull out all stops to make this campaign shine. Depending on your business, it could be a special promotion or a survey asking for feedback, or simply a note asking if they're still interested in receiving your emails.

It doesn't hurt to check the history of your subscriber. Have they ever downloaded an e-book or previously signed up for a course? If so, try sending them similar content it worked for me!

About a year ago, I signed up for an email newsletter for the sole purpose of downloading a digital marketing e-book. I never bothered to unsubscribe after getting the book, but I largely ignored their subsequent emails. Months later, the company sent another email that caught my eye, offering a white paper on a similar topic. In this case, both parties won: I got a new resource and the company converted a graymailer into an active user.

Unfortunately, not all scenarios end like that. If your graymail users still don't bite, then it's time to let them go.

While removing your hard bounces and graymails will most certainly lighten your list, just remember that these addresses are doing more harm than good by hanging around. By removing them, your engagement and deliverability rates will go up, and you'll start to see a more accurate picture of how well your campaigns are performing.

But remember, cleaning your list shouldn't be a one-time deep clean. There isn't an industry standard on how often email lists should be cleaned, but no matter which time frame you decide on, just remember to stick to it.