Is there an add on that will automatically address a cc to Assistant when I email Lawyer?

I would like to find an add on that let’s me associate a lawyer and their assistant. Then, when I compose an email to the lawyer, the add on automatically adds a cc to the assistant.

Do you know an add on that will do this?

In your webmail? In Thunderbird?

Either or both.

I’ll take what I can get.

Thank you.

I can imagine hypothetically that an extension could inject a content script into a page that watches for changes to the “To” field. When there is a change, it would compare the contents with its list to determine who to cc for those addressees and add that address if it is not already present. I guess it should also run automatically in case in case the page is opened as a reply and no further changes to the “To” field are needed. If the name in “To” is changed, though, should the cc be removed? That part could get a little tricky. Also, timing, because some webmail sites take a while to populate address fields, the script would need to make sure its changes are not too early and then overwritten. Or I guess it would automatically run again? Hmm…

Such an add on would be very handy for me and, I would imagine, a lot of other people as well.