How to remove an extra email address from the contact's E-mail field in B24?

Question

Bitrix24

Good afternoon!

Tell me, or give links to the documentation, which describes with examples how you can delete data from fields in the Lead, Deal, Contact, Company.
What is the point? I torment the e-mail tracker.
It is necessary to make sure that a Lead and a Task are created for each letter - I did this.
There were two problems.
1 - A contact is automatically created for each such lead.
2 - Creation of repeated leads is done through the mail settings

AND through the substitution of the "From" and "Reply-to" fields in the forwarding box settings.

As a result, a Lead and a Contact are created for each letter. But the problem is that the contact in this case is duplicated.
In addition, the contact contains two E-mail addresses: one is the correct client, the second is the forwarding box address, which is indicated in the screenshot.

Two questions:
1. How to prohibit the creation of duplicates in contacts?
2. How to automatically delete a specific address in a lead and contact?

Thank you.