When comparing Mozilla Thunderbird vs Nylas Mail, the Slant community recommends Mozilla Thunderbird for most people. In the question“What are the best e-mail clients for macOS?” Mozilla Thunderbird is ranked 3rd while Nylas Mail is ranked 15th.
Ranked in these QuestionsQuestion Ranking
Pro Free (as in freedom and beer)
Pro Lightning Calendar and Address Book integration
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 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 Very reliable
Version after version, Mozilla Thunderbird works as expected.
Pro Available on Linux, OS X and Windows
Pro Large assortment of plugins available
Mozilla Thunderbird offers a huge amount of extensions to expand the usability and options of the client.
Pro Tabs for navigation
Pro Great design
Simple, easy to use, easy to learn user interface.
Pro Open Source
You can change it, customize it, and make plugins for it.
Currently there are plugins for GitHub integration, Templates, and Translation, and the potential for many more to come. It's built on top of Chromium so making plugins for it will not only be easy for Chrome app and extension developers, but it means that it has the potential to use Chrome plugins, too.
Pro Dynamic, secure, private
You can use Nylas' servers, or run your own mail server on your own computer.
Pro Works with Exchange accounts
N1 is one of the few 10 Windows Desktop Clients to offer support for a business Exchange email account (the Windows Native Client is one of the few alternatives that also work). It seems that this niche is really dominated by Outlook, and few solutions are available that prioritize it.
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 Terrible integration with macOS
Simple things - drag/dropping pictures doesn't work, for instance.
Con Outdated interface
Thunderbird's interface is very outdated and unpleasant.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 Some features require a monthly subscription
Con A lot of RAM memory used
This email client uses a lot of RAM (random access memory) - actually using more than Chrome (albeit with a lot of tabs open).
Super slow to sync. not really supported anymore as they're focusing on their API.