DLP prevent from: or sender: mail property is controlled

[Miro]

Hello,

when the user sends an e-mail from the common mailbox common.mailboxATcompany.com,
the field from: contains common.mailboxATcompany.com
and at the same time the field sender: will be added in the e-mail and contains sender.mail.addressATcompany.com.

When I setup rule to block mails and add exception in the Sender field for common.mailboxATcompany.com it does not work and mails with from: common.mailboxATcompany.com are blocked.

It does not work when both properties (from: and sender:) are filled and common.mailboxATcompany.com is in from:

It looks like DLP Prevent controls only sender property and not from property.

Which of these properties (from: or sender:) does DLP Prevent (mail) control?

Thank you
Miro