How does the manager send a greeting letter to the lead?

This is a traditional case. The standard functionality of Bitrix24 for sending mail does not guarantee even 98 percent of the probability that the letter will be delivered to the recipient.

Therefore, I give the solution - our integration. A lot of our customers make mass mailings through integration. In the application even there is an allocation of access rights.

Yes, of course, that's what I'm talking about. Your managers must manually open the contact, the lead or the dealer, and send him a single letter through integration. Then look at the statistics for reading this single mailing.

Technically, there is no such implementation in any integration for Bitrix24. Moreover, it was not even technically possible before and so our customers use the functionality that is in the integration. I suggest all the same to take advantage of the scenario that was proposed in the commentary above.