Everyone gets to choose how they want to handle their situation.
However, I don't think that is entirely true unless an opening is given to send email.
Emails has its pros and cons. Snail mail has its expense and inconvenience but if you ask any lawyer, if you are trying to establish gravitas, snail mail using Certified Mail is the way to go. Alternatively, send a Fedex or UPS letter is powerful also.
I keep trying to tell people in these cases to stop focusing so much on "outlawyering", "convincing", or asking for approval. But no matter how many times I say it, so many become sheep and "follow the rules" anyhow.
I am telling everyone that symbolically, there is nothing more powerful than using snail mail using Certified Mail to deliver a message. It is so powerful a symbol that I have had recipients over the years refuse to accept my Certified Mails out of fear. They simply didn't want to accept service and read the contents of MY letters. Refusal of service worked in my favor because it was reputationally damaging to the other side when it came out.
Yes, Certified Mail can get expensive but my intent is not to get into a debate indefinitely. It has strong symbolic value to deliver a strong message directed at some conclusion. That is my advice.
I have a long track record of successfully winning (or at least partially so in those I didn't) the disputes both in writing and in person on all kinds of matters (traffic, credit disputes, customer satisfaction, etc.) When I play, I play to win. There are some "shortcuts" that simply undermine what you are trying to do. I continue to say that emails undermine that effort in having gravitas in your communication.
People may think they are saving time and money on one hand but they lose something else in another. If people must, I would send a FAX over email anytime. FAXes have higher symbolic value than emails. In fact, emails are among the lowest.
The best analogy I can give is that if you received a hand-written letter from anyone, how would you react? The handwritten letter is so rare today, it is practically extinct or certainly an anomaly.
Turns out they send letters and emails either way!