Email List Health Report (Free List Grade)
Paste a list or open a CSV and get a grade from A to F, with a count of every problem: duplicates, invalid and mistyped addresses, throwaway and role emails, free vs business domains, your top domains and, if you like, domains with no mail server.
Runs 100% in your browser. Your list is never uploaded (the optional mail server check sends only domain names). You can also drag a file onto the box. Spreadsheets: save as CSV first.
How the grade is worked out
Every list starts at 100 points. Points come off for problems, weighted by how much harm they do when you send:
Why these weights? Hard problems are addresses that will almost certainly bounce or never reach a person, and bounces are what mailbox providers watch most closely. So each 1% costs 4 points: a list where 5% of addresses are broken gets a B at best. Role addresses (info@, sales@) usually work but are shared inboxes that complain and unsubscribe more, so they cost a little. Duplicates cost the least, because they don't bounce: they just annoy people and inflate your counts. Removing them is easy with the download below.
Shares are worked out from the rows that have something in the email column. Blank cells are counted and shown, but they don't lower the grade.
How it works
- Finds the email column. For a spreadsheet, the tool picks the column headed "Email" or the one with the most addresses. You can choose another column in the box that appears.
- Checks the format of each address: one @, allowed characters, a real-looking domain and ending.
- Finds duplicates three ways: exactly the same, the same apart from capital letters, and Gmail addresses that reach the same inbox (Gmail ignores dots and anything after a +).
- Looks at each domain: likely typos of big providers (gmial.com, yahoo.con), about 8,900 known throwaway services, free providers like Gmail and Yahoo, and business domains. Role addresses such as info@ and sales@ at business domains are counted too.
- Optional mail server check: looks up the MX records of up to 300 of your most common business domains through public DNS, to find domains that can't receive email at all.
- Downloads: a cleaned CSV (you choose what to take out, typos can be fixed), a problems CSV with a reason for every row, and a plain-text summary to share.
Lists of 100,000 rows or more work fine. The work is done in small slices so the page stays responsive.
What a grade can't tell you
A list can get an A here and still bounce. The report checks the format of each address and facts about its domain. It can't tell whether [email protected] still works at that company, or whether a Gmail account was closed years ago: only the receiving mail server knows that. Old lists are the riskiest. If a list hasn't been mailed for six months or more, check the mailboxes before you send.
Related free tools
Related guides on EmailNa
What the email list health report does
Before you send to a list, it helps to know how healthy it is. This report reads every row and counts what could go wrong: invalid and mistyped addresses, duplicates, throwaway and role addresses, and domains that can't receive mail. It sums it all up in a grade from A to F, with the formula shown, so you can decide whether a list is ready to send or needs cleaning first.
Benefits
- One grade, clearly explainedA to F, with the score and the exact formula, so you can explain it to a client or a boss.
- Every problem countedCounts and percentages for invalid format, typos, throwaway, role, free and business addresses.
- Three kinds of duplicateExact copies, copies in different capital letters, and Gmail dot and +tag versions of one inbox, shown separately.
- Top 10 domainsSee who is really on the list: mostly Gmail, or mostly companies?
- Dead domain checkOptional MX lookup for up to 300 domains, with a progress count.
- Clean list and problem listDownload a cleaned CSV with every column kept, and a problems CSV with the reason for each row.
- Big lists welcome100,000 rows are checked in seconds, in your browser.
Who it is for
- A business owner about to email a customer list for the first time in a year.
- A marketer handed a list by a colleague, a client or an event organiser.
- A freelancer or agency checking a client's list before importing it into Mailchimp, Brevo or Klaviyo.
- Anyone comparing two lists to see which is in better shape.
How to use it
- Paste your list, or open a CSV or TXT file. Excel users: save the sheet as CSV first.
- Check that the right email column is picked, then press Check my list.
- Read the grade and the table. Run the mail server check if you want dead domains included.
- Choose what to take out and download the cleaned CSV, the problems CSV or the summary.
Your privacy
Your list is read and checked by code running in your browser and is never uploaded. If you run the optional mail server check, only the domain names (like example.com) are sent to Cloudflare's public DNS service, with Google's as a backup. The addresses and the rest of your list never leave your device.
Frequently asked questions
What is a good email list health score?
A or B (80 or more). That usually means fewer than 3 to 5% of addresses have hard problems. A C or lower means enough bad addresses to push your bounce rate past what Gmail, Yahoo and Outlook tolerate, so clean the list before you send.
Why don't the categories add up to the total?
Because they overlap. One address can be a duplicate and a role address at the same time, and free, business, typo and throwaway are all worked out from the domain. Each row is counted once in the grade's "hard problems", though, so nothing is penalised twice.
What counts as a duplicate?
Three things, shown separately: the same address typed the same way, the same address in different capital letters ([email protected] and [email protected]), and Gmail addresses that reach one inbox because Gmail ignores dots and anything after a + sign. Unique emails counts each inbox once.
Does the report check whether each mailbox exists?
No. It checks the format and the domain, which catches a lot, but only the receiving mail server knows whether a mailbox is real. Veml checks that for every address on a list, without sending an email. It doesn't detect spam traps, and no checker can do that reliably.
Why are free providers like Gmail not counted as a problem?
Because they aren't one. Gmail, Yahoo and Outlook.com addresses are real people. The free vs business split is there for B2B senders who want to know how many work addresses they have. To separate them, use the business email filter.
Is my list uploaded?
No. Everything runs in your browser. The only thing that ever leaves your device is a domain name, and only if you press the mail server check button.