TinyLetter
Used by 4 peopletinyletter.com ↗

“I also use TinyLetter to power the "Subscribe to my Blog" link, but I have yet to send a single issue.”
Ellen Chisa Interview, Product manager (Kickstarter) · via Uses This 
“I send my weekly newsletter with the help of TinyLetter.”
Ann Friedman Interview, Journalist (New York magazine, Tomorrow) · via Uses This