Websites That Use Mailcheck in 2026

We track 332,032 websites that use Mailcheck in 2026. Those sites span 55 industries and 25 countries. The crawler re-checks each domain daily. So the count moves as sites adopt Mailcheck or drop it.

Mailcheck belongs to the JavaScript libraries category. Sites in that category tend to share a similar stack. As a result, they often share buying patterns too.

The table above shows a sample of 100 matched companies. Each row carries an industry, a country, and a live domain. You can search it, sort it, and export it.

Adoption is not spread evenly. Instead, a few industries account for most of the matched sample:

• Information Services5%
• Education Management5%
• Information Technology and Services4%
• Construction4%
• Wellness and Fitness Services3%

Information Services leads that list. However, the long tail matters just as much. Adoption reaches 55 industries in total. So you can narrow the list to the segment you sell into.

The matched companies sit in 25 countries. These lead the sample:

• 🇺🇸 United States 34
• 🇧🇷 Brazil 10
• 🇨🇴 Colombia 7
• 🇨🇦 Canada 6
• 🇲🇽 Mexico 5

United States is the largest single market in this sample. Because the country is stored per row, you can filter before you export. That keeps your outreach inside one timezone and one legal regime.

Start with the table above. Then follow these four steps to turn it into an outreach list:

1. Filter the sample. Narrow by industry or country until the rows match your ideal customer profile.
2. Export the domains. Share the page to unlock the CSV, or sign in for the full dataset.
3. Find the people. Run each domain through Domain Search to pull every work email behind it.
4. Verify before you send. Pass the results through the Email Verifier so your bounce rate stays low.

Working at volume? Push the whole export through Bulk Tasks instead, or call the Domain Search API directly from your own stack.