What problems is Canary Mail solving and how is that benefiting you?
I was a happy user of Spark until they started all over again with their new Spark Desktop. I went through a whole iteration of email clients, from Newton to Postbox, from Apple Mail (+Butler) to Mailspring, from Airmail to you-name-it. I found it annoying that while each email client has some advantages, each client also had disadvantages that made working with them problematic. Each client managed to be an obstacle rather than a useful tool. Mailspring probably came close. Spark forces you to do mail their way, with difficult access to folders and labels and forcing you to compose new emails in the main window. Postbox is awkward in terms of rendering html. Apple Mail refuses to offer a good snooze function. Airmail and Newton are basically half-finished pieces of software that cannot be considered fully functional. I didn't mention Edison, which, like Mailspring does a good job. And Outlook refuses to work with Gmail labels.
What I like about Canary is that it offers all the good points of the above mentioned emails clients and none of the disadvantages. Robust snoozing, sending and deleting delays, Send later.... all the bells and whistles. It also gives perfect access to labels and folders. There are two ways of highlighting important emails: (1) you can favorite senders/domains (2) you can pin emails for follow up. Pinned emails can be collapsed so new emails to appear within sight.
The reason why I initially overlooked Canary is that it appeared to not render logo's and graphic ux elements correctly. Turns out antialiasing isnt perfect on non-retina screens. Once I realized this, I was able to get over that. Now I'm hooked. Review collected by and hosted on G2.com.