ESPs are the providers of email services where we all get our email. Gmail is one of the more commonly known providers. When you send a broadcast email, ISPs use a number of factors in whether that email should be delivered or not -- referred to as email deliverability. Some of these factors include:
DNS sender authentication, the cleanness of your email list, the desirability of your email content, and more. One of the more important characteristics is your sender reputation, which is how an ISP identifies you as a legitimate sender of email. You can think of this as like your credit score but for email. So here, we will look at your sender score and what you should know.
Like your credit score, your sender score builds over time. It's not based on a single email. Instead, every time you send an email campaign, the ISPs collect more data about your email performance and how to score you as a sender. The big items that go into your reputation are:
This is not an exhaustive list and each ISP factors sender reputation a little differently but this should give you an idea of how a sender score develops over time.
Never purchase an email list. This is first for a reason. Purchasing an email list is a very poor practice for communicating with people that no association with your organization or campaign. The recipients will likely find your email intrusive and will report you as spam. This will have an instant and long-standing impact on your ability to deliver future emails to your entire audience.
Keep your email list clean. Remove bounces, spam reports, and unsubscribes from your email list quickly. Sending to a known bounced email repeatedly is a targeted behavior for many ISPs.
Purge and prune your list of people no longer interested in your email. If you have people on your list that have not opened/read an email or taken any actions toward your campaign, then it can be better for you if they are just not on your email list. Removing them can have the effect of increasing the engagement rate of future emails by only sending to engaged audience. A good practice is to segment out non-participants and send an email, asking if they are still interested. Tell them they will be opted out unless they re-subscribe.
Send useful content that your audience engaged with. There is no better way to create a goo sender reputation than to have a good percentage of your audience engaged in your content by reading, responding, and clicking. it goes without saying that this would be great for your organization as well.
Tools to check your sender reputation