Email Deliverability Techniques

Warming up your IP addresses prior to sending out your campaigns can be incredibly helpful in making sure it doesn’t seem like you’re a spammer. Email service providers flag dormant IP addresses when they begin sending to big lists without prior history. This brings us to another point about regularly sending emails in order to not only establish consistency with ESPs, but this will also create a cadence for your recipients to expect emails and drive down your unsubscribe clicks. If your sending platform allows it, we suggest limiting the amount of emails you send to different domains until you have properly warmed your IPs.

For example, when emailing major emails service domains like Yahoo, Gmail, Hotmail, or AOL make sure you are not emailing more than 200 messages per day per IP for the first five days. After you have consistently sent your campaigns for five days, then you can move on to double your output every day. This technique may seem like it takes a while to ramp up, but it certainly pays off as you realize that your conversions are predictable and consistent without being blacklisted by ESPs.

In order to ramp up deliverability most effectively, there are some steps you should take to maximize the sender score you are assigned by email providers. First, warm up your existing IP by sending 50-200 emails per day depending on the domain. Then, send only to addresses that have opened at least one of your messages in the past 30 days. Limit your starting volume to 3,000 addresses and send to those subscribers only for the first 3 days, before increasing the volume. Next, increase the volume to 4,500 subscribers with opens in the last 30 days and send to this volume for two days. Finally, increase the volume every two or three days by 50% of total volume and after 10 days you can start doubling the volume.

Inbox testing can be powerful because different ISPs use spam filters and without inbox testing sender reputation will suffer because you may not know how different email settings and message content will affect your deliverability. Tracking delivery, IP, domain health monitors is a great way to stay on top of your campaigns as well as identifying if your domain or IPs have been blacklisted. Being blacklisted on different websites like Spamhaus is an extreme disadvantage because these lists are published and ESPs will instantly be alerted of your sending, resulting in your emails being pushed to the spam folder or even bounce regardless of address validity. Finally, you should certainly clean your list of bounces, traps, and complainers by partnering with an email verification service to increase list quality, sender score, domain, IP reputation, delivery, and inbox rates.