How to mark forwarded mails

[mw62]

Mails sent to my Gmail account are forwarded to my Outlook account.
Within Mailwasher they show up twice: column Account : gmail and outlook.

So far I manually tagged (for delete) the gmail entries within Mailwasher.

It seems I can't create a filter on my gmail-account (From/To/Delivered to, etc.) as it will also mark the mails to outlook.

Is there a way to mark those mails (i.e. forwarded mails from Gmail to Outlook)?
There is way to select 'Account' when creating a filter.
There are: From', 'Subject', 'To', 'Reply-To', 'Cc', 'Bcc', 'Body', 'Received', 'Delivered-To', Return path, Header, Size, but not 'Account'.

Thanks.

[rusticdog]

We are adding the option to filter by account, in the meantime these emails should have X-Forwarded lines in the header.

Suppose I forward my GMail to forum@firetrust.com, it would look like

X-Forwarded-To: forum@firetrust.com
X-Forwarded-For: xxxxxxxx@gmail.com forum@firetrust.com

Presumably then, create a filter to look at the header, in plain text
X-Forwarded-For: xxxxxxxx@gmail.com forum@firetrust.com
Should catch those emails.

[mw62]

I can't detect any X-Forwarded stuff. Under 'Source' the only 'X'- entries are
X-Customer-ID, X-Database-ID, X-Content-ID, X-Job-ID, X-Contract-ID
all with random numbers and figures.
Under 'General' Email header: there are no X-entries either.

The below example involved some kind of notification.

SnagIt-02112018 084651.png (12.22 KiB) Viewed 2298 times

[rusticdog]

Can you click on the Source tab of that screen and send me the contents to forum@firetrust.com