We have an on-premises Exchange server 2019, where we want to create a mail flow rule which BCC's any emails sent with attachments to "firstname.lastname@example.org"
With the rule enabled we were getting many false positives, e.g. emails with clipboard / screenshots being sent to users that would also trigger the attachment rule. So I came up with the solution to add an exception when the email contains a jpg, jpeg etc.
Now this works just fine but we want to take into consideration all scenario's where we want to prevent internal users from taking multiple screenshots of company data and sending it via email. so we'd want to implement a limit of at least 5mb, But there are no exception filter that says "size is less than or equal to" it only has "size greater than or equal to"
If I create another rule for email size limit, we will create duplications where an email might be sent to the attachments folder twice?
Is there any solution to our issue?