Yahoo/Hotmail emails - API bad request


I’m running into some trouble with yahoo/hotmail email addresses going into hubspot. I have a custom form sending basic user data into Hubspot via AJAX, this works great except when I try to submit with a Yahoo or Hotmail email address, these are rejected with a 400 bad request error. Any other email works without issue. I’m currently handing this by replacing “yahoo” with “yashmoo” before submission (these ‘yashmoo’ emails go into HubSpot just fine) and then manually editing them with the correct email, but would like to find a sustainable solution.

I’m wondering if perhaps there’s an encryption requirement or similar for these types of addresses? Or if anyone has any thoughts on why this might be happening?


@lfideler HubSpot forms have a built in option to block email addresses from free email providers. You’d need to disable that feature by editing the settings for the email field in that HubSpot form, and uncheck the option to block free email providers.