Would it have worked to forward the mail from your work email system to your personal email?

If it’s a big corp, they probably have strict data exfiltration policies for corp email.

Maybe this one email would have been fine, but if it gets tripped, it’s not worth the headache.

These same corps have opinions on where users can be logged into Slack as well. And ffiw most enterprises that have this kind of device management don't allow login via magic links via email anyways.

Yes, accurate, I was able to access some slack workspaces but not the main one without putting the invasive management profile on my phone

It wouldnt have worked any differently from the first qr code with quarantine, and been a flagged violation, eventually

Now your private email contents are subject to discovery.

Assuming we are talking about discovery in a civil lawsuit involving your employer the party opposing your employer can ask for all documents you have that are relevant to the lawsuit. It is then up to you to turn over those documents.

If they specifically ask for documents that are not relevant or if their request is too broad so will produce a lot of irrelevant documents your company's lawyers will tell them no.

By the time someone is actually specifically giving you a list of things to turn over that includes your private email it will only be asking for things that are relevant. Most of your personal email will be excluded.

Genuinely: why? All that is related to the business email is already accessible, it's just been forwarded elsewhere. The info is already known. What's to discover?

To discover where else you then subsequently forwarded it.

I'm not suggesting this is actually a problem, but that's how an argument could go.

It indicates that you used your this other email for work purposes. The point is that they don't know what's in there, and they want to see if you discussed stuff relevant to the case. The judge will deny such a request as a fishing expedition if there is no basis for believing that you used your personal email for work purposes. But if it is discovered that you started sending work emails to that address...