Where can I download the design for email letters?

Question

Layouts and prototypes

Interested in where you can get or see designs for email letters. Perhaps there are ready-made solutions.
Does anyone know of a site where this can be found? Paid resources are also considered.
It is highly desirable that the resource be alive and constantly updated
. I tried to search, but all links lead either to mailing list services, where there are templates, or to articles with collections of the same examples of email letters. These options do not like. templates are the same everywhere and already outdated in design. You can find something creative, but very rarely.