When comparing Mail Pilot vs Mailspring, the Slant community recommends Mailspring for most people. In the question“What are the best e-mail clients for macOS?” Mailspring is ranked 9th while Mail Pilot is ranked 20th. The most important reason people chose Mailspring is:
Mailspring has great integration with gmail features and tags.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Good security features
There are options to display URLs you get in emails, or to disable pictures by default if you are afraid of getting malicious data from suspicious emails.
Pro Doubles as a to-do application
Mail Pilot turns emails into tasks. It has a built-in system of setting reminders and collecting emails into groups as to-dos.
Pro Great integration with Gmail
Mailspring has great integration with gmail features and tags.
Pro Neat UI
The UI is very well designed and neat.
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 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 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.
Cons
Con Makes a huge mess of IMAP mailboxes
Builds many new categories and basically uses IMAP as a database. Makes it difficult to work alongside other mail clients or webmail.
Con Not reliable
Mail Pilot seems to be riddled with bugs and glitches.
Con Not for everyone
Since it's mainly focused to turning emails to tasks and a strong believer of "inbox zero", it may not be suitable for everyone's workflows.
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 Slow updates and bug fixes
It takes months to fix some simple bugs. For example, they can't fix bug with notifications on mac OS from April 2019! Upd: they fixed it after 6-7 months
Con Unstable, have to keep fixing passwords
You have to keep "updating the password" because it continuously finds it hard to sync with multiple Outlook accounts.
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 addressbook
Con No way to see messages as plain text
And HTML is only optional.
Con Does not support Microsoft Exchange
Con Very limited user interface
No way to see the messages as a list, no way to rearrange views.
Con No portable windows (.zip) bundle available
Con Does not support POP
Just IMAP.
Con Does not support multi-user installation (Windows)
But instead installs to the user's home directory.
Con UI is sluggish (Windows)
Click and only after a tiny delay (~half second) something happens.