Tag blockquote in email

Good day.

In the editor and when ticket is displayed, the quota is highlighted with a border on the left - this behavior is described in the RT css. But upon receipt of the letter, the tag style is lost and the quota is highlighted simply by indenting from the left edge. Somehow you can specify at the level of RT style of this tag in mail html? I mean like than -

blockquote style="…"

set blockquote style in template.

but… maybe there is a more correct way?