In some cases, an email may be marked as spam because the sender authentication fails.
If the emails are legitimate and should still be delivered by us, you can whitelist them accordingly. It is important to note that the checkbox for sender validation must be ticked for the whitelist entry. You will find step-by-step instructions below.

The procedure is the same for SPF, DKIM and DMARC errors.

It is also advisable to inform the sender that the configuration is probably incorrect.

1. Log in to the Control Panel as an administrator
2. Navigate to the customer's domain via the scope selection at the top right
   
3. Select the menu item Deny & Allow Lists
   
   
4. Press the +Add entry button
   
5. Now enter the owner. If the field remains empty, the entry is active for the entire domain. An individual user can also be entered in the field.
6. You can define the value under Type
   
   
7. Enter the value to be whitelisted in the Value field. Depending on which type you have selected, a corresponding value must be entered. For example, the header-from address must be used for the "e-mail address" type. 
   
8. Under Bypassed filters, check the box to Sender validation. At the end, the entry will look like this: