Not sure if relevant to OP but in my case, I needed a way to route multiple emails (Gmail and own domain) to a catch all account. Found ForwardEmail service and after a very easy setup, it works fantastic. They even have SMTP.
For client, I use Thunderbird and Vivaldi’s own email features.
Thinking about this, the only ancient information we are still able to access is painted or edged on stone or clay. How about some sort huge wall with thousands of QRcode like engravings?