What are the drag'n'drop editors for creating html-letters like in mailing services for the "teapot" user level?

Question

Email

There is a need for periodic beautiful adaptive letters to clients and in connection with this I am looking for some simple solutions for dummies, desktop or in the cloud, so that you can stupidly go in, block the letter, copy the code, paste it into the body of the letter in the mailer and send it. Is there anything similar?
Any service for mass mailings has such a function built in, but this does not suit me, because I need to make these letters with individual content.
Who faced?

Answer 1

Here are a few such editors (but Mailchimp should not be discarded):
https://beefree.io/
mailmalade.com
https://www.inkbrush.com/
https://mosaico.io/

Answer 2

https://mailchimp.com/ for example, allows you to create letters with individual content.
Or what does individual content mean to you?

Answer 3

Stripo.email - has an HTML editor and convenient Drag-n-Drop. Mailchimp and other ESPs have 1-click export