Grant rights to forward a blocked email?

I’m hoping someone can help me. I am working with a client and a policy they have works correctly 95% of the time, but 5% of the time it generates a false positive and blocks the file from being sent. I was wondering if there is a way to grant a user the rights to inspect and forward an email?

Scenario :

• A message is sent from a user via email.
• The message is blocked by DLP.
• The user’s manager is notified of the blocked message.
• The manager inspects the message, determines it is a false positive.
• Info Sec/DLP engineers inspects the message and determines the message is a false positive.
• The manager then forwards the message to the initial mail recipient.

Is it possible to give the manager rights to forward the email? If so, how?

I’ve read about Forward Mode, but I’m not sure about it’s real world application.