BLocking incomming email

Copper Contributor

My company is using 365 for email. Recently, we have started seeing an uptick in spam/phishing emails. To combat this a colleague setup a mail flow rule in exchange admin to block emails from a list of email addresses.

 

When I open the rule, it tells me it contains 120 email addresses to block. I add a few more and the number never goes above 120. Is there a limit to the number of email addresses I can block with a single rule? Should I create additional rules? I'm afraid that addresses are dropping off the list as I add new ones.

1 Reply

@michaelbeaver 

 

Yes, there is limitation at around 120 to 150 Email address per mail rule, btw, you might consider using the Tenant Allow/Block List in Microsoft Defender for Office 365, which allows for a higher number of block entries