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A whitelist is a curated list encompassing email addresses, IP addresses, domain names, or applications, strategically employed in cybersecurity. This list serves as a protective shield against potential threats capable of disrupting local networks or the broader internet. It is meticulously crafted and managed through stringent policies and access permissions overseen by IT administrators.
Frequently, emails from our clients or partners end up in the spam folder due to various filters or inadvertent blacklisting. This results in emails from specific domains being incorrectly labeled as spam. Another common reason for emails being marked as spam is their origin from unknown sources, leading to neglect of SPF or DMARC checks. To prevent these issues, it’s essential to add specific domains and all associated email addresses to the whitelist.
Exchange Online’s whitelist serves as an exception to the established security configuration but can be circumvented by the program’s anti-spam mechanisms.
There are instances in Office 365 where you might want to whitelist emails:
If the user wants to filter the emails based on Words in the Subject, they can go for this-
The Subject or Body and next Subject include any of these words
If a user wants to prevent spoofing of an allowed domain, they can go for this
A Message header and next includes any of these words.
Now under “Enter text” and dmarc=pass under “Enter words….” Add Authentication-Results
Here put the header to X-ETR and the value to Bypass spam filtering for the Domain.
In this process, we will utilize Microsoft 365 Defender, which allows the domain to bypass spam protection and sender authentication in order to whitelist it.
Whitelisting a domain is a valuable measure to prevent your essential messages from being marked as spam. However, there are instances when even after whitelisting, messages end up in the spam folder without your awareness. To ensure the safety of your important data, it’s advisable to maintain backup copies of your files. For this purpose, we recommend using a professional Office 365 Backup tool, such as Kernel Office 365 Backup & Restore. This tool is designed to back up entire mailboxes, and you can explore its functionality through a free trial version, simplifying your backup process in just four easy steps.
Now that you’ve learned how to whitelist a domain in Office 365, you can explore additional articles of mine that provide insights into Exchange Online, Microsoft Outlook, Microsoft Teams, and SharePoint Online, helping you further enhance your understanding.