With the premium product offering you are able to manage whitelists and blacklists. if you only have the basic product offering you will need to upgrade and should contact firstname.lastname@example.org.
To allow the domain administrator to remain in control over the filtering, it's possible to whitelist/blacklist a recipient.
This can be found in the web interface under the Whitelist/Blacklist menu items:
All filtering checks are disabled for whitelisted recipients. We recommend only using the recipient whitelist for exceptional cases such as special abuse@ or postmaster@ recipients.
Emails to recipients listed on the blacklist will be automatically rejected. The messages are NOT quarantined. The messages are rejected with a 5xx SMTP error code, so legitimate sending SMTP servers will generate a bounce message to the sender.
To whitelist/blacklist a specific recipient address, the local part of the address should be entered. For example if your domain is mydomain.com and you add nofilter to the recipient whitelist, all emails sent to email@example.com not be scanned for spam. To whitelist/blacklist all recipients for a domain (so all emails sent to the domain are not scanned/blocked), you can enter the wildcard * for the local part.