What is the source of this issue?
Since the implementation of Mailinblack, you are no longer receiving internally exchanged emails. What is the cause?
The Sender Policy Framework (SPF) is a field present in the TXT record of a domain. This field lists the authorized IPs to send emails on behalf of the domain. It appears like this: v=spf1 mx include
.mailinblack.com include.protection.outlook.com ~all
This helps legitimize the sending IPs of a domain.
If the sending IP address is not listed in this record, Mailinblack will classify the email as spam.
How to resolve it?
Log in to your Mailinblack account and go to your Protect area.
Click on the "Settings" menu, then the "General Settings" tab.
Go to the "Exclusions from SPF checks" section and add the IP address, domain, or email addresses for which you wish SPF verification not to be applied.
Then, validate the record. Emails originating from these records will no longer be marked as spam in Mailinblack and will be directly delivered to you.
Following the implementation of this exclusion, we will no longer be able to prevent the reception of potential spam.
To prevent your internal emails from being marked as spam, it is recommended to update your SPF record to legitimize your email sending, or to keep your internal emails on your mail server.