Hello, I want to ask is there a way to make a signature with html from a site?

For example, I administer a lot of mail to colleagues and I want to change everyone's signature.


Let's say I set the path to the signature - mydomain.com/signature.html

I wrote there "Greetings from us today is the month of October" and after a while to change the html code with "Greetings from us, today is the month of November"


I will be very grateful if you tell me if there is such an option