Reference by a former professor using personal email address?

[LordBONSAI]

Hello everyone. My first post at the forum. I reached out to one of my undergrad profs with whom I established good rapport, only to learn that he's no longer teaching at the university (for personal reasons). He said he's self-employed right now, meaning he doesn't have a university email address nor university headed paper. I found out that most law schools I'm applying for ask for a least one "academic" reference letter, and I have no idea whether it's okay for him to use his personal email. All I can find is that OLSAS seems to say no, and I quote "enter a business/university email address rather than a personal email address". Well the thing is he's my top choice for referees. We know each other well since I took 4 different courses with him and even participated in his research project. So I'd really like his reference to be submitted. I do have another professor willing to write on my behalf although I had much less interaction with the latter.

My situation is sorta unusual, but if anyone here has ever been in the same boat with me, please feel free to give your advice. 

Thank you all.

Edited August 20, 2021 by LordBONSAI

[MSK2021]

Barring some stupid and inflexible policy, it should be fine. I imagine this will be a bit of an issue for a few years in light of events at Laurentian.