prevent that a mail disclaimer rule is added to mail send from internal domainname by external servers

Question

Hello,

We are testing with a mail disclaimer to be added to e-mails originating from outside of the company. This is working great.

However we have a number of external services that send email on behalf of our domain name to internal people where the disclaimer is shown. I would like to prevent this. Is it correct when I say that I actually have to add the IP addresses of my SPF record (the mailserver allowed to send email from my domain) in the line.

"Except if the sender ip is"

If i do this will the disclaimer no longer be added to this type of e-mails?

Thanks!

Answer 1

Start by telling us how you are adding the disclaimer? If it's via mail flow rules, simply add an exception to the rule based on the sender's IP address, email address, or even "keywords" in the subject. If you are using the built-in "external in Outlook" feature, you can define an Allow list as detailed here: https://learn.microsoft.com/en-us/powershell/module/exchange/set-externalinoutlook?view=exchange-ps