An email address can be rejected by DQE when the submitted value does not match a valid email format, cannot be validated with enough confidence, or belongs to a domain that does not allow reliable validation.
Common reasons
- the email address format is invalid;
- the domain does not exist or cannot be resolved;
- the mailbox cannot be confirmed;
- the domain applies private or restricted validation policies;
- the address contains a typo or unsupported character;
- the request is missing required parameters or uses the wrong service configuration.
What to check first
- Verify the spelling of the email address.
- Check that the domain name is correct.
- Remove spaces or hidden characters before submitting the request.
- Test another address from the same domain to check whether the behavior is domain-specific.
- Confirm that the request uses the correct endpoint, licence, and environment.
Private or restricted domains
Most email domains can be checked by DQE. However, some private or restricted domains apply their own policies, which may limit the information available during validation or affect the returned status.
When to contact DQE Support
If you believe an email address should not be rejected, provide the submitted email address, the DQE response, the expected result, the request timestamp, and the environment used for the request.