How Do You Block Email Domains on Every HubSpot Form at Once?

How do you block email domains on every HubSpot form at once?

In HubSpot, open Settings, go to Marketing, then Forms, and open the Submissions Settings tab. Enter the domains you want to block in the "Email domains to block" field, separated by commas, and click Save. You can also turn on "Block free email domains." HubSpot says the settings then apply across all your HubSpot forms.

This tutorial is for one specific situation: a B2B team running several HubSpot forms, tired of junk submissions from personal inboxes, competitors, or a few known spam domains, and tired of fixing each form one by one. If you manage more than three or four forms, the account-level setting is the one to use.

Everything below follows HubSpot's own knowledge base article on blocking form submissions by email domain, which HubSpot last updated on September 2, 2026. Menus move, so if a label looks different in your portal, check that article for the current version.

Who can use this setting?

HubSpot lists the feature for Marketing Hub and Content Hub on the Starter, Professional, and Enterprise subscriptions. You also need permission to edit forms. If you do not see the Submissions Settings tab, check your subscription and your user permissions before assuming the feature has moved.

Permissions trip people up more than plans do. A marketer who can build landing pages may still lack form editing rights, especially in portals where an admin locked settings down after a past mistake. Ask your HubSpot admin to confirm your role before you start, so you do not spend twenty minutes hunting for a tab you cannot see.

It also helps to know who else owns forms in the portal. An account-level block affects every HubSpot form, including ones a colleague built for recruiting, partner sign-ups, or customer support. Tell those owners before you change anything, because a rule that makes sense for demo requests can break a careers form.

Which domains should a B2B team block?

Block domains that never become customers and only create cleanup work: known spam sources, competitors whose staff submit forms to research you, and test domains. Be careful with free email providers. Blocking them suits demo requests from companies, but it can lose real buyers who use a personal address.

I separate the decision into two lists. The first is a short list of specific domains, which is low risk because you chose each one for a reason. The second is the free email provider switch, which is a policy decision, because it blocks a whole class of people at once.

For the free email switch, think about who you sell to. If your buyers are mid-market and enterprise teams, nearly all real leads arrive with a work address, and blocking free providers mostly removes noise. If you sell to founders, consultants, or very small businesses, many genuine buyers use personal inboxes, and blocking them costs pipeline you will never see.

There is a middle path if you are unsure. Instead of blocking free addresses, you can let them through and flag them for review. I covered that approach in how to flag free email sign-ups with a HubSpot workflow. Flagging keeps the lead and adds a step. Blocking removes the step and the lead.

How do you set up the account-level block step by step?

Click the settings icon in HubSpot's top navigation bar. In the left sidebar, go to Marketing, then Forms. Open the Submissions Settings tab. Type the domains to block in the "Email domains to block" field, separated by commas, and click Save at the bottom left. For free providers, turn on "Block free email domains" and save.

Prepare your domain list before you open HubSpot. Put it in a document with one line per domain and a short reason next to each, such as "competitor" or "spam source." That document becomes your record of why each domain is blocked, which matters months later when someone asks why a lead could not submit.

When you paste the list into the field, separate the domains with commas, as HubSpot's article describes. Check the list once more for typos. A misspelled domain blocks nothing, and a too-short entry could block a domain you did not mean to touch.

Click Save. HubSpot says that once saved, any blocked domains or free email providers apply across all your HubSpot forms. That is the whole point of the account-level setting: one list, maintained in one place, instead of a different list on every form.

How do you block domains on just one form instead?

Open Marketing, then Forms, and edit the form. In the form editor's left sidebar, click the settings icon and open the Submission settings tab. Enter domains in the "Email domains to block" field using only the root domain, such as gmail.com, without www or the @ symbol. Then click Review and update.

A per-form block is useful when one form has a different audience. A demo request form might block free providers while a newsletter form accepts them. A partner application form might block competitor domains that a general contact form allows.

The root domain rule matters. HubSpot's article says to enter only the root domain, without the www prefix or the @ symbol. Entering "@competitor.com" or "www.competitor.com" is a common mistake, and the safest habit is to use the same plain format in both the account-level list and per-form lists.

HubSpot's article does not spell out how per-form lists and the account-level list interact on a single form. Rather than guess, test it on your own portal with a test address, as described below, before you rely on a mix of both.

How do you test that the block works?

Test with a real submission from a blocked domain on a live form. HubSpot says a visitor using a blocked domain is prompted to enter a different email address before submitting. Confirm that prompt appears, then confirm that an allowed work address still submits normally and creates or updates the contact.

I test three cases every time. First, a blocked specific domain. Second, a free provider address, if you turned on that switch. Third, a normal work address from an allowed domain. The third test is the one people skip, and it is the one that catches a list that blocks too much.

Use real forms on real pages, not just the form preview, because what matters is the experience on your website. If your forms are embedded on a Webflow site, test the embedded version on the live page, not only inside HubSpot.

What does this setting not cover?

HubSpot describes the setting as applying across your HubSpot forms. Forms built elsewhere, such as native Webflow forms that send data to HubSpot through Zapier or another integration, are not HubSpot forms, so they need their own validation. Check every path that creates contacts, not only HubSpot forms.

This gap is easy to miss. Many B2B sites use a mix: a HubSpot form for demo requests, a native Webflow form for the newsletter, and a booking tool for calls. Only the first is covered. If junk is arriving through the others, the HubSpot setting will not help, and you will need validation in the website form or a filter in the integration.

If your site uses the Webflow-to-HubSpot route, my tutorial on connecting a Webflow contact form to HubSpot with Zapier shows where a filter step fits. A single filter that checks the email domain before the contact is created does the same job for that path.

How should you maintain the blocked list over time?

Review the blocked list every quarter. Remove domains that no longer cause problems, add new spam sources you see in submissions, and check that the free provider decision still matches your buyers. Keep the reason for each domain in a shared document, so the list does not become a mystery.

Lists like this grow and rarely shrink. A domain blocked during one spam wave stays blocked for years. Sometimes that domain later belongs to a real company, or a competitor's employee changes jobs and becomes a buyer. A quarterly review takes ten minutes and prevents those quiet losses.

Pair the review with a look at form performance. If demo requests drop right after you turn on the free provider block, that is a signal worth reading. My view is that fewer, cleaner leads are fine, but only if you confirm the ones you lost were not real buyers.

What should you do next?

Write your list of domains to block with a reason for each, decide whether free providers should be blocked for your audience, and tell other form owners. Then set the account-level block in Submissions Settings, test three cases on live pages, and check any contact paths that bypass HubSpot forms.

I build websites and the automations behind them for lead generation, and clean form data is where good routing and reporting start. If you want help tightening the forms and CRM flow on your Webflow and HubSpot setup, reach out at pravinkumar.co. Let's chat.