imapsync - Console-based utility for migrating IMAP mailboxes.
Blogsend - Automagically send your blog posts straight to your readers
Gmvault - Backup the emails in your Gmail account.
Visual Marketing Automation - An insanely fast automation builder by ConvertKit
Cryoserver - Cryoserver is an all-in-one email archiving solution that empowers you to preserve your email in a tamper-evident archive, making you transform your data into a useful archive for everyday use.
Landing Pages in MailChimp - Easy to build, custom landing pages for free