If your mail server uses LDAP or Active Directory, we recommend using that and disabling the catch-all feature:
Using Active Directory (Exchange) or LDAP to set up valid email addresses
Without the catch-all feature, you must maintain a list of valid email recipients that SpamHero should accept mail for. Any email sent to an unlisted address in the SpamHero control panel will be rejected.
With the catch-all feature enabled, SpamHero accepts mail for any address on your domain, so you don’t need to manually maintain a list of valid recipients.
The catch-all feature is enabled by default on all domains but can be disabled if needed.
If you receive a high volume of messages for invalid recipients, it could push your account over the inbound message limit, resulting in overage charges. Disabling the catch-all prevents messages to invalid addresses from counting toward your total.
For most domains, keeping the catch-all enabled does not typically cause overages.