When comparing Mail.app vs Spark, the Slant community recommends Spark for most people. In the question“What are the best e-mail clients for macOS?” Spark is ranked 4th while Mail.app is ranked 5th.
Ranked in these QuestionsQuestion Ranking
Pro Integration (with other Apps/Hardware)
One thing Apple does well is to integrate its apps and hardware. The mail app is no exception. If you must be in the hermit kingdom, at least take advantage of the (often excellent) features provided.
Pro Will probably be enough for a sizable chunk of users
Since it's the built-in Mac email client and is quite complete feature-wise, most users will not really need any other third-party applications out there. Mail.app should be enough for their needs.
Pro Easily annotate pictures or sign documents inside the client itself
Mail.app has powerful markup tools which let users add annotations to images or even sign documents they got through email without ever leaving the client.
Pro Smart folders on steroids
- You can choose out of tenths of mailheaders (several hundreds including virtual headers)
- "<header> is (not) in <folder> <header>" operator which enables you to do cool filters
- Each smart folder can have smart subfolders by an user definable key
Pro Shows threaded view with snippets in middle panel
Pro Can be easily extended
If the basic features inside Mail.app are not enough, it can easily be extended through plugins to add new features.
Pro Custom quick swipe features
Pro Robust customization options
Pro Syncs across devices
Pro Unified inbox
Pro Free snooze options
Con No option to snooze emails
You can not snooze emails to view later. This makes it hard to keep the inbox clean at all times since you have to read every email and choose to delete or keep them the moment they arrive to do so.
Con Missing lots of advanced features
Out of the box, Mail.app may not have as many features as some other options. This can be mitigated with plugins though. But that is not a perfect solution since third-party plugins may not be very reliable in the long run.
Con Really bad reliability
Database engine gets stuck consuming 100% of one core; crashes; a 40GB log file has been spotted.
Con Updates may break plugins
Apple is known to make API changes to Mail.app when updating which break a lot of plugins.
This can be very annoying for users whose workflow heavily relies on plugins, since they have to wait for plugin developers to make the changes needed to fix any issues brought by the update.
Con Poor performance for some users on El Capitan
Con Poor calendar integration in exchange mode
- Sends statistical data to several services known for bad privacy policies (Google, Facebook), also there's no way to opt out.
- Automatically creates an acount with the first address entered and subscribes you to their newsletter.
- Stores credentials for your email accounts on their servers.
- Stores your emails on their servers to push them to your devices.
- Server infrastructure seems to be located in the US.
Con Doesn't support many services
Many services such as Spam filters, Pocket, and other apps are not supported.
Con Doesn't show the counts of emails next to the folders
- On the Mac platform will show +999 for the folder that contains more than 1000 emails.
- On the iPhone, the platform will not show the counts next to the folder unless they are new emails.