Mails.so review (2026): is it worth €48 a month?
Email validation API and list checker with flat monthly plans
Black Friday: is there a Mails.so sale?
Mails.so report card
Fair · out of 4.0 · graded Nov 13, 2026
Best for an email validation API with flat monthly plans
Mails.so validates addresses by list or API on flat monthly plans, from €48 for 10,000. The first month is 90% off and then renews at full price, the free allowance is a one-time 50 credits, and we only saw euro prices.
Who Mails.so is for
- Fits if you want a flat monthly price instead of buying packs
- Works for people who also want an email finder
Who Mails.so is not for
- Watch out: the 90% first-month discount lasts one month, then the plan renews in full
- Skip it if you want a free plan, since it's 50 credits once
- Pricey if you validate small amounts, as plans start at €48 a month
- Watch out: prices were read in euros and the dollar price is unconfirmed
Why Mails.so gets a 2.2
Five grades, each with its reason. The GPA is their average: an A is 4 points, an F is none.
- CValue for money€48 a month for 10,000 validations, which is near the category's $49 dearer quarter once converted. The dollar price is unconfirmed.
- CFree plan and trial50 free credits on sign-up with no card, once. No monthly free plan.
- CFeaturesList validation, an API and an email finder. Only the three paid plans are listed, with no pay-as-you-go pack.
- CEase of useNo store rating on record. You upload lists or use the API.
- BPlatforms and integrationsWeb and API with Mailchimp and HubSpot links. No apps.
What these grades rest on. Graded from this listing, whose facts were read from Mails.so's own pages on 13 November 2026. Not based on using the product, and shorter than our full reviews. How we review and grade.
Make Mails.so? Put this grade on your site
Paste this where you want the badge. It links here and follows the grade if it changes. About badges
<a href="https://toolgpa.com/tools/mails-so#review"><img src="https://toolgpa.com/badge/mails-so.svg" alt="Mails.so: 2.2 GPA on ToolGPA" width="196" height="56"></a>Where Mails.so stands among email verification and deliverability tools
Mails.so's GPA of 2.2 is higher than 23 of the 61 other email verification and deliverability tools we grade, and level with 13.
It stands best on platforms and integrations (B, above 28 of 61) and worst on features (C, above 0).
Its paid plans start at about $53.63 a month, against a middle price of $21.50 for the category: 34 of the 43 others that charge start lower.
On features, ease of use and platforms it scores 2.3 out of 4. 8 tools score higher and cost less.
Each grade against the category
Every bar is all 62 email verification and deliverability tools we grade, cut by the letter each got. Mails.so’s own letter is outlined.
- CValue for moneyAbove 9 of 61, level with 35
- CFree plan and trialAbove 9 of 61, level with 43
- CFeaturesAbove 0 of 61, level with 45
- CEase of useAbove 2 of 61, level with 50
- BPlatforms and integrationsAbove 28 of 61, level with 33
Price against what you get
Each dot is one of 45 email verification and deliverability tools. Further left costs less, and higher up scores better on features, ease of use and platforms. Point at a dot to see which tool it is.
Features, ease of use and platforms, averaged
What paid plans start at, a month (each step along is roughly double) →
- The best score at each price
- Has a free plan
- No free plan
Keep Mails.so, or make your own?
Keep it
Nothing Mails.so does is plain enough to make in a weekend. The 2 things listed below take a company.
It costs $643.51 a year.
What you could not
- Checking that an address exists without writing to it.
- It plugs into other products, Mailchimp and HubSpot among them, and has an API.
What this rests on. Mails.so’s listing: what it does, where it runs, what it plugs into and what it costs. It is a judgement about the kind of software this is. We have not built a replacement for it, and making your own means looking after it too. How we decide, and every tool’s verdict.
What is Mails.so?
Mails.so is an email validation service with a web checker, list upload and an API. Paid plans are monthly and all include API access, list validation, an email finder and Mailchimp and HubSpot integrations. The pricing section sits on its homepage and is shown in euros.
Worth knowing
- Prices were read in euros; a US dollar view could not be read, so the dollar price is unconfirmed.
- The 90% first-month discount applies to the first month only; the plan then renews at full price.
- The free allowance is a one-time 50 credits, not a monthly free plan.
- Only the three paid plans were listed; there is no separate pay-as-you-go pack on the page.
Key features
- List validation
- Upload a list to check its addresses, or paste single addresses into the checker on the homepage.
- Validation API
- Every paid plan includes API access, for checking addresses at signup or inside other software.
- Email finder
- An email finder is included on all three paid plans.
- Mailchimp and HubSpot integrations
- Listed on every paid plan for cleaning lists held in those platforms.
- Top-ups
- Extra validations can be bought at any time on Pro and Business at a stated per-validation rate.
Mails.so pricing
As of Nov 13, 2026, Mails.so is a paid product with a free trial, starting at €48 per month for 10,000 validations, shown in euros.
- Starts at
- €48 per month for 10,000 validations, shown in euros
- Free plan
- None
- Free trial
- 50 free credits on sign-up, no credit card required
| Plan | Price | What you get |
|---|---|---|
| Pro | €48per month for 10,000 validations | First month €4.80 (90% off). 5 concurrent validations; top-ups at €0.005 per validation. |
| Business | €98per month for 50,000 validations | First month €9.80 (90% off). 5 concurrent validations; top-ups at €0.002 per validation. |
| Unlimited | €498per month for unlimited validations | First month €49.80 (90% off). 10 concurrent validations. |
Read from mails.so on Nov 13, 2026. Prices change, so confirm with Mails.so before you buy.
Ways to pay less
- Other savings90% off the first month
The homepage shows each paid plan at 90% off for the first month, then at full price. No end date is shown.
Stated on mails.so
Works with
Mails.so alternatives
- Mails.so vs ZeroBounce
Free plan · from $39 one-time
- Mails.so vs NeverBounce
Free trial · from $8 one-time
- Mails.so vs Emailable
Free trial · from $38 one-time
- Mails.so vs MillionVerifier
Free trial · from $39 one-time
Common questions
Does Mails.so have an Android app?
No Android app was listed when its pages were read on Nov 13, 2026. Mails.so is listed for Web.
Does Mails.so have an iPhone app?
No iPhone app was listed when its pages were read on Nov 13, 2026. Mails.so is listed for Web.
Is Mails.so open source?
Mails.so is not described as open source on its own site, as read on Nov 13, 2026.
Does Mails.so have an API?
Yes. Mails.so offers a public API, according to its own site.
Sources for this page
The prices, plans, platforms and features above were read from these pages on Nov 13, 2026.