What's the best way to sign documents from a civilian laptop, trapped in the new mil mail system?

ARNet portal remote through citrix on a civ laptop and CAC reader, then just use Outlook (if the ARNet Portal is still available https://aramp.usar.army.mil .)

And it looks like you should be able to download and upload documents on teams with a civ windows machine, just worked when I tried it. That does not work on linux.
Truth be told, when we can finally sign docs in Teams, that will save tens of thousands of hours a year.

Also, if you to get GFE, (Govt Furnished Equipment, and every MDAY/TPU commander should have one) everything you want to retain for future records (all documents, all pst files of everything you sent and received on Outlook, etc), you can just burn to dvds before you give the laptop back. That's how fulltimers manage switching laptops every 2-5 years.

Thanks for the responses. It validates my current SOP, and challenges.

Completely different area of discussion, but I can sit pretty where I am in my current USAR slot till I retire, and not be exposed to the headaches this causes on a grander scale than my personal affairs.

I will not be exposing myself to commander duties/slots unless I can be confident I can navigate the administrative requirements I barely skated by as a CO while a LT. Even the challenge of a Gov issued device poses problems when the device needs a hard line ARNET connection to receive updates. This poses even further problems when the Unit is hundreds of miles away and the possibility of an entire system reload is required when hard line ARNET activity cannot be guaranteed.

It's more common than one thinks with AT that are nowhere near an ARNET, and holiday months like DEC potentially not having an BA weekend causing two periods a year where as many as 60+ days between connectivity.

As petty as it sounds, something this insignificant can be the foundation of a unit meeting readiness metrics or not.

Army 365 will continue to evolve. There is a plan for a BYOD solution. It will mean that you will not be able to store products on that local computer, but that is not inappropriate. I cannot give you a decent forecast date, just that it is coming.