HowTo (optionally) use whole e-mail as new issue (not just last reply)

I’ve set the “reply by e-mail”-feature in GitLab using a Postfix mail server with sub-addressing and now I’m able to open new issue via e-mail, which is a very, very nice feature.

But in the work process currently in use (which will hopefully be made obsolete by GitLab in some near future) we often end up with issues whose description should be the whole e-mail body including all the previous quoted messages (for example, our customers could discuss something internally first and then send the whole mess to us). GitLab by default parses the e-mail it gets to only extract the very last message.

Is there a way to turn this off? Maybe a slash-command I’m unaware of or some settings?