Issue Summary

Unable to add private domains to External account types in customer access.

List of valid domains here: https://data.iana.org/TLD/tlds-alpha-by-domain.txt

Steps to Reproduce

• Global settings > Products > Customer access > under account type choose External 
• Try to add the private domains for example abc.lan > Save 
• The error pops-up saying "We couldn't update the customer access settings. Refresh the page and try again."
• Even when they are added manually to the site emails send from private domain to mail handler doesn't create a ticket but says "Email doesn't belong to domains allowed in customer access settings."

Expected Results

.lan or any other private domains are allowed to be added successfully in customer access email domains. 

Actual Results

The below error is thrown instead -

We couldn't update the customer access settings. Refresh the page and try again. 

Workaround

If you're operating within a private network and have a small number of users, you can manually add them to the project. Since the standard sign-up and invitation process relies on email — which may not work in this setup, the admin will need to manually set or update passwords for each user. Then the users will be able to raise tickets from portal.