How to subscribe to the mail sending event in CRM?

Question

Bitrix24

There is a letter item in the deal. In it, you can create and send a letter. Does B24 have an event that you can subscribe to to run your code before sending the email and add your parameters to it? As in BOS onBeforeEventSend.

Answer 1

UPD Try BeforeSendMail
Use OnBeforeEventAdd

Answer 2

OnBeforeMailSend