When comparing Blue Mail vs Mozilla Thunderbird, the Slant community recommends Mozilla Thunderbird for most people. In the question“What are the best native e-mail clients for Linux?” Mozilla Thunderbird is ranked 2nd while Blue Mail is ranked 8th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Highly customizable notifications
Offers a lot of different preferences (like Quiet Hours, Custom Sounds, Vibrate, LED Light, Snooze Alerts, etc.). You can set different preferences for each of your accounts.
Pro Integrated calendar
Pro Supports multiple e-mail accounts
Gmail, Yahoo Mail, Outlook, Alto, iCloud, Office 365, IMAP, POP, etc.
Pro Unified inbox
Pro Clustering of e-mails by sender
Pro Supports Android Wear
Pro Free (as in freedom and beer)
Pro Available on Linux, OS X and Windows
Pro Very reliable
Version after version, Mozilla Thunderbird works as expected.
Pro Good filtering system
Mozilla Thunderbird offers a flexible filtering system with the ability to set flags and read/unread, as well as sort/assign to new mail directories. There are also numerous plugins available to assist in the filtering.
Pro Large assortment of plugins available
Mozilla Thunderbird offers a huge amount of extensions to expand the usability and options of the client.
Pro Great flexibility
More options and extended settings than most power users could dream of. Get it working how YOU want.
Pro Tabs for navigation
Pro Lightning Calendar and Address Book integration
Pro Consistent and involving a moderate learning curve
The app design of Mozilla Thunderbird has not changed significantly since its beginning, making its learning curve almost non-existent.
Pro Send large files easy
Install pCloud plugin for Thunderbird and your files (upto 20 GB free storage included) will be received as download links
Cons
Con Development slowed to only focus on stability and security
Mozilla Thunderbird has slowed down its development of features to only focus resources on security and stability.
Con Outdated interface
Thunderbird's interface is very outdated and unpleasant. It feels more like a Windows XP application than like a modern MacOS one.
Con Terrible integration with macOS
Simple things - drag/dropping pictures doesn't work, for instance.
Con Subject lines can (temporarily) disappear from the list
This is sporadic behavior.
Con Serious bugs
Clicking on a subject line can bring up the wrong email.