Case generated from reply of another case

[Emmker]

I have setup case generation from group email (Microsoft 365).
Everything works fine, but when I receive e reply from some of the companies that use a specific crm program, the reply generates another case.
I think that their crm strips out the "code" that espo reads to categorise the email to the case that belongs.
Is there another way I can manage these "rogue" emails and put them in the correct case without generating another one?

[Vadym]

Hi Emmker,

Could you provide more details with screenshots so we can investigate this issue in more detail?

[Emmker]

Hi Emmker,

Could you provide more details with screenshots so we can investigate this issue in more detail?

I solved it. But..
The issue was that a company crm was messing the the recognition system of espocrm, and it didn't recognized the email as a reply of the case>
I created workflow injecting in the Name and body of the outgoing emails a "Tag" with the case number.
And some workflows that manipulated the incoming emails if they have that "Tag", and puts them in the correct Case, deleting the extra case that the "rogue" email has created.

But now that I sold that, another Case related problem came to light.

I have NO filters in the Group email account. Thus every email that is coming to the system, if it does not belong to a case and does not have my "Tag", should create a new case.
But I have several emails that have no parent case.
The list includes all the emails with "Delivery Status Notification" in their subject, which is welcomed, but I have not specifically told the system to not include them.
Is there some kind of default filtering in the emails that create a case, and if there is one, can I change it?
Given that the senders of the emails that not generate a case is around five from the 5000+ that I have, and furthermore the emails of the same senders have no problem to get into a case if they answer an email from an already opened case from another one.

It drives me insane

Edit: the group email is from the Outlook Integration