Corporate signature in letters?

Question

Email

How to organize a corporate signature in e-mail if
- more than 100 employees (and you can't force everyone to adhere to corporate style)
- Mozilla Thunderbird, Outlook or Yandex.Mail are used
- No access to MX domain settings, DNS, etc.
- It was possible to quickly selectively edit this signature

Answer 1

No administrative resource? If not, then no way - there is no feedback, the user will see that he can score on the requirement - and he will certainly score :)
For Outlook, there are policies and common templates. For TB, there are forced profile settings that are not allowed to be edited. For YaP, I don’t know what is there, but if it is corporate, there should be a single admin muzzle.
But once again - without observing the Principle of the First Leader , all your efforts will turn into "pshhh..."