Why does an error occur in the layout of email templates for Bitrix?

Question

1C-Bitrix

Made layout for email templates for email events. We saved it as a theme for email messages in the Settings->Product settings->Mail events->Themes
section. There was a problem when the letter arrives at the mail, the layout is not displayed correctly. When generating an email, Bitrix takes all CSS styles from the header section and adds them to the style attribute of the html layout tags. Some of the tags were completely duplicated. As a result, the layout went. With what it can be connected?

Answer 1

What a question, such an answer.
Because mailers love high-quality layout, and not some left-wing generation.