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With billions of emails sent every day, it’s no surprise that more than 80 percent of these land in spam. But how do you keep yours out of the dreaded spam box? The answer is email warm-up.

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What Exactly Is Email Warm Up?

When you open a new email account, you get a predetermined daily limit for sending emails. This is assigned by email service providers like Gmail and Yahoo! Mail. New accounts have a significantly lower limit than used ones, causing inevitable email deliverability issues.

You need to build a good sender reputation to stretch your limit, and email warmup helps you do exactly that. The email warmup process involves regularly sending, receiving, and opening emails. You also need your emails to be opened by your recipients and have them take out your emails from spam.

You cannot possibly imagine pulling this off manually.

Enter OutReachBin. Our peer-to-peer network consists of thousands of real businesses, all of which are working together to increase each other's email reputation.

outreachbin homepage

When you connect an email to OutReachBin, it will automate the entire email warmup process, helping you build your sender reputation, and stay away from the spam box.

Learn how Monsy skyrocketed their email camapigns and generated revenues through Outreachbin's managed services

How We Conducted The Research

We collected a total of 3.3 million data for our OutReachBin database from January to July 2021. During this time, we sent nearly 2 million emails for email warmup, and nearly 800k emails as replies, averaging more than 285k total emails sent per month.

From a total of 1373 unique email provider IDs, we randomly selected a sample of 500 email provider IDs. For each email provider ID, we recorded the sending date of the email from the respective email providers.

After a number of follow-up emails and replies to these follow-up emails, the email moved out of spam. Then we recorded the exact date the email moved out of the spam box.

Once we had the two timestamps, we calculated the difference between the sending date and the moved-out-of-spam date.

Testing Our Method

Before we start working on larger samples, we tested our method on a much smaller one. Here’s a sample of 10 randomly selected email provider IDs, sorted by sending date.

email warmup data set outreachbin

Then, we let OutReachBin go to work.

It automated the process of sending emails, following them up, and replying to these follow-up emails. Once the emails moved out of spam, we recorded when it happened.

OutReachBin email warmup dataset

The next part was easy. We calculated the time it took for each email account to move out of the spam box.

email warmup dataset

In our randomly selected sample of 10 email provider IDs, we noticed that the warmup time ranges from 2 to 135 days. The mean in this sample is 25.8 ~ 26 days, while the median value is 12.5 days.

We can understand the reason behind this huge discrepancy by taking a look at the scatterplot below.

warmup time scatterplot

The warmup time for email provider ID #22 shot up to 135 days - clearly an outlier in the sample. This causes our mean to move away from the median warmup time.

Analyzing The Sample

The impact of outliers can be minimized with larger samples, which is why we did the same calculation first on 100 records, followed by 200, 300, 400, and finally for all 500 records.

Here’s what the result looks like after rounding up the average number of days it took to warm up the emails.

moving out of spam chart

We can notice that as the sample size approaches 500, the number of days decreases. One of the reasons for this is that a larger sample size results in a more precise mean value, as it smooths out the effect of outliers.

warmup scatterplot comparison

You can see in the scatterplot that the outliers are more prominent in the samples with 100 and 200 records, which have a mean warmup time of 28 and 21 days respectively. This is similar to our test sample which yielded a mean warmup time of 26 days.

Then, as the sample size increases, the mean warmup time goes down to 17 days for 300 records, and 15 days for 400.

The scatterplot for a sample of all 500 randomly selected records looks like this:

warmup scatterplot

The average warmup time for this sample was recorded at 13.41 ~ 14 days. This is a huge improvement if we compare it to our test sample’s result of 26 days.

After sending out 3 million emails and analyzing the records of over a thousand email provider IDs, we can finally give you an answer to the question you have asked us a lot.

How Long Does It Take For Email Accounts To Warm Up?

2 -3 weeks - if you’re looking for a short answer.

Two weeks might seem like a lot of time. But if you consider the alternative, which is manually sending hundreds of different emails from hundreds of email accounts with a good reputation. Not to mention opening the emails in all accounts, replying to them, and taking them out of spam.

This could take you months, if not years to accomplish.

In our study with 500 samples, nearly 73% of email IDs were warmed up within 2 weeks, and a whopping 87% moved out of spam within 3 weeks. Only 8.6% of email IDs took more than a month to warm up.

email warmup time graph

So when it comes to email warmup, we recommend waiting 2-3 weeks for your emails to move out of spam.

Get More Done With OutReachBin

With OutReachBin, you just need to connect your email service provider, set your options, and sit back to watch the magic happen. OutReachBin will help you stay out of the spam box, and build your sender reputation steadily over time.

What are you waiting for? Get started with OutReachBin today, and never worry about email deliverability again!