Really Good Emails - A large collection of good product email design.
Posteo - Web- and IMAP-based email service. 2GB cost 1€/month.
Good Email Copy - Email copy from great companies.
Inbox.lv - Inbox.lv Mail
Good Sales Emails - Best sales emails from great companies
CounterMail - Countermail is a web-based email service. It is hosted in Sweden. Its focus is on privacy.