When comparing Mutt vs Mailspring, the Slant community recommends Mutt for most people. In the question“What are the best native e-mail clients for Linux?” Mutt is ranked 2nd while Mailspring is ranked 6th.
Ranked in these QuestionsQuestion Ranking
Pro Terminal based
Pro Small and efficient
Pro Highly configurable macros
Pro Threads emails
Pro Active development
Even though it was first released in 1995, Mutt still enjoys an active community following it and having new releases constantly.
Pro Work with regular expressions
Mails can be filtered, deleted, flagged, etc. with regular expressions which makes mail management very efficient.
Pro Compose mails in your favorite editor
Edit mails efficiently with an editor you already can work fluently with.
Pro Neat UI
The UI is very well designed and neat.
Pro CPU / battery efficient
Mailspring uses a C++ sync engine designed to be as efficient as possible, so you can leave the app running and not see your laptop battery life drain away.
Pro Read receipts and link tracking
Activity tracking is built into Mailspring so you get notified as soon as contacts read your messages and can follow up appropriately.
Pro Great integration with Gmail
Mailspring has great integration with gmail features and tags.
Pro Unified inbox
Using a single inbox for all of your email accounts helps you get more done in less time. Mailspring supports every major mail provider—Gmail, iCloud, Office 365, Outlook.com, Yahoo!, and IMAP/SMTP—so you have a single, streamlined command center for all your messages.
Pro Snoozing support
You can swipe to archive / snooze messages and specify when you'd like them to resurface in your inbox.
Pro Unlimited number of accounts
Only in the paid version though.
It runs inside the terminal so it doesn't display HTML email, fonts, or graphical elements.
Con Can't use without creating a Mailspring ID
There is no need to create a third party ID for an email client. What if the Mailspring closes in the future - can't install a previously downloaded Mailspring software any more to continue using it or access your stored emails?
Con No addressbook
Con Pro subscription model
To use some features, like contact profiles and link tracking more than a few times a month, you need to pay for a Pro subscription.
Con No portable windows (.zip) bundle available
Con Does not support POP
Con Very limited user interface
No way to see the messages as a list, no way to rearrange views.
Con No way to see messages as plain text
And HTML is only optional.
Con UI is sluggish (Windows)
Click and only after a tiny delay (~half second) something happens.
Con Does not support multi-user installation (Windows)
But instead installs to the user's home directory.