[Evolution] Deleting annoying CAUTION msg's

[Joakim Tjernlund <Joakim Tjernlund infinera com>]

Our company injects a CAUTION msg in mails which are received externally(see below). If
I try to remove this msg(the yellow box), the WHOLE mail is deleted.

Jocke
-------- Forwarded Message --------

Date: Fri, 20 Oct 2017 11:10:08 +0200
Subject: Re: [gentoo-dev] Manifest2 hashes, take n+1-th
To: Gentoo Development <gentoo-dev lists gentoo org<mailto:Gentoo%20Development%20%3cgentoo-dev lists gentoo 
org%3e>>
Reply-to: <gentoo-dev lists gentoo org>
From: Dirkjan Ochtman <djc gentoo org<mailto:Dirkjan%20Ochtman%20%3cdjc gentoo org%3e>>
CAUTION: This email originated from outside of the organization. Do not click links or open attachments 
unless you recognize the sender and know the content is safe.

On Fri, Oct 20, 2017 at 12:49 AM, Gordon  wrote:
On Thu, Oct 19, 2017 at 5:32 PM, Hanno  wrote:
On Thu, 19 Oct 2017 21:08:40 +0200
Michał  wrote: