Previously we kicked off our series on fighting SPAM in Office 365 and I promised some unique tips on battling the bad guys. However, before we go diving into building elaborate rules to snag SPAM you’ll want to lay down the ground work to prevent said rules from stopping important messages. One of the most common Office 365 concerns I see is how to ensure mail from specific vendors or customers is not getting caught in Quarantine or getting rejected, these rules will do just that. Since the options here are pretty straight forward I’ll let the images do most the talking.
To create each of these rules you'll need to sign into the Exchange Online Control panel @ https://outlook.office365.com/ecp click on the Mail Flow tab and then the plus sign create a new mail flow rule.
This first rule will give you a spot to add specific IP addresses that you do not want to get caught in SPAM filtering, we can add single IPs or CIDR notation.
With IP whitelisting in place we’ll turn our focus to email domains.
Lastly we’ll tackle the one-offs. There is bound to be a few users with gmail.com addresses that you’ll want to whitelist without trusting every Gmail user in the entire world, this rule does just that. Simply type each email address and then click “check names” to add them to VIP list.
There you have it, 3 simple rules to keep your users happy and the emails pumping. Please let me know in the comments if you have any questions or if you have any tips on how you tackle SPAM on your tenant. Be sure to check back in for future posts in our series on beefing up the SPAM fighting skills of Office 365.