Email validation · Use cases · HubSpot
Use case
HubSpot email validation, via API.
You can validate emails for HubSpot by calling Trueguard's email validation API from your HubSpot form workflow or backend before a contact is created. It checks format, MX records, SMTP validity, mailbox deliverability, disposable domains, catch-all, role-based, and free-mail in one call, so fake and undeliverable addresses never enter your HubSpot contacts. There is no native app required.
Before the contact
One request, four possible answers.
Try one address.
The same check your HubSpot workflow would call. 10 free checks a day, no key and nothing sent to the address.
Or try
The cost of junk contacts in HubSpot.
Sender reputation damage from dead contacts
Wasted contact quota on junk records
Skewed segmentation and workflow data
Catch-all contacts cleared as deliverable
How do you validate emails for HubSpot?
No marketplace app to install. One API call you wire into your own flow.
Call the API from your form handler
Or from a custom-coded workflow action
Let the verdict decide what HubSpot does
Which contacts should enter HubSpot and which should not?
Each status maps to a contact-management decision before the record enters HubSpot.
Status
What it means
HubSpot action
Format, MX, and SMTP confirm a real, deliverable mailbox.
Create the HubSpot contact and proceed with normal nurture.
Deliverable at the server but unconfirmed at the mailbox. Catch-all, role-based, or free-mail flagged here.
Create the contact with a flag property. Route to a review list or lower-priority workflow before outreach.
Bad format, no MX, or the server rejected the address. Undeliverable.
Do not create the contact. Reject at the form or skip the sync. This address will bounce.
The server blocked the probe or gave no clear answer.
Create the contact with a flag. Monitor for engagement before investing in heavy outreach. Re-check if needed.
Four things to know before you wire it up.
Why does HubSpot say "email validation failed"?
HubSpot's check stops at format and domain
No HubSpot app required
Segment on role-based and free-mail
What does the API response look like?
One POST from your form handler or workflow action. The status decides whether the contact is created; the signals underneath tell you why.
// in your form handler, before the HubSpot contact is created
const check = await fetch(
"https://api.trueguard.io/v2/email/validation",
{
method: "POST",
headers: {
"X-API-KEY": process.env.TRUEGUARD_KEY,
"Content-Type": "application/json"
},
body: JSON.stringify({ email })
}
).then((r) => r.json());
if (check.deliverability.status === "invalid") {
return reject("Please check your email address");
}{
"email": "name@gmail.com",
"rawEmail": "name@gmail.com",
"syntax": { "isValid": true },
"deliverability": {
"status": "safe",
"isSmtpValid": true,
"isMxValid": true,
"isCatchall": false,
"isInboxFull": false,
"isDeliverable": true,
"isDisabled": false,
"mxRecords": [
"gmail-smtp-in.l.google.com",
"alt1.gmail-smtp-in.l.google.com",
"alt2.gmail-smtp-in.l.google.com",
"alt3.gmail-smtp-in.l.google.com",
"alt4.gmail-smtp-in.l.google.com"
]
},
"domain": {
"name": "gmail.com",
"age": 11363,
"isLive": true,
"isRisky": false
},
"quality": {
"isDisposable": false,
"isFree": true,
"isRole": false,
"isSubaddress": false
}
}Frequently asked questions.
Still deciding? Contact support or read the API reference.
How do I validate emails for HubSpot?
You call Trueguard's email validation API from your HubSpot form workflow or your backend. If your form posts to your own server first, validate there and only create the HubSpot contact for accepted addresses. If the contact is already in HubSpot, a custom-coded workflow action can pass the email to your endpoint and write the result back as a contact property. Either way, it is one API call you place in a flow you control.
Is there a native Trueguard HubSpot app or marketplace integration?
No. There is no Trueguard app in the HubSpot marketplace. You validate emails by calling the API yourself, from your form handler or a custom-coded HubSpot workflow action. That is deliberate: doing it as a direct API call lets you control exactly when the check runs and what HubSpot does with each result, rather than inheriting a connector's fixed behavior.
Why does HubSpot say email validation failed?
That message is HubSpot's own built-in form check, not a Trueguard result. HubSpot validates at the format and domain level: it rejects malformed addresses and can block free or personal domains when a form requires a business email. It does not run an SMTP check, a disposable check, or catch-all detection. So an address can pass HubSpot and still be undeliverable. Trueguard adds that deeper layer on top of HubSpot's native check.
Does this stop disposable and fake emails from becoming HubSpot contacts?
Yes. Disposable detection checks each address against a continuously updated registry of throwaway providers, and the deliverability check catches addresses that look real but reject mail. Catch-all addresses come back risky unless a second check confirms the mailbox, so you can handle them with care. When you call the API before creating the contact, those addresses are flagged or rejected before they ever enter your HubSpot list.
Will it improve my HubSpot marketing email deliverability?
It removes the addresses that were guaranteed to bounce, which protects the sender reputation that gets your real mail delivered. We do not promise a specific deliverability number, because your actual results depend on your list, your content, and your sending practices. What validation does is keep invalid and undeliverable addresses out of HubSpot, so your marketing sends are not dragging dead contacts that pull your reputation down.
Can I validate existing HubSpot contacts, not just new form fills?
Yes, by calling the API against those contacts yourself. Export or list the addresses, run them through the validation endpoint in a batch from your own script or a workflow action, and write the results back onto the contacts. Be clear that this is your own batch call, not a native sync. There is no automatic background process; you decide when to run it and what to do with the verdicts.
Is there a free tier to test with HubSpot?
Yes. The first 100 validations a month are free with no card, which is enough to wire the call into one HubSpot form workflow and confirm contacts land clean before you scale. For a quick single-address check outside HubSpot, the free email verifier at https://trueguard.io/email-verifier runs the same validation in the browser. When you need more volume, the paid plan is $49.99 a month for 50,000 validations.
Keep junk out of HubSpot from the first form.
100 validations a month, free, no card. Wire one call into your form workflow and watch the contacts land clean.
Get your free API keyNo credit card required.
