...and I've (not-quite) literally tried them all:- Apple Mail- Webmail- Fancy webmail extensions like Boomerang, Gmelius, etc.- Outlook- Thunderbird- Spark- Hey- Superhuman- Front- Newton- Mail Butler- Airmail - Mailbox (RIP)- Google Inbox (RIP)- and I'm sure I'm missing others...Even when I try a new one, I always come back to Polymail.The app slam dunks on both function and form. It's clean, minimal, easy on the eyes, and highly-functional for Inbox Zero. It offers the laundry list of now-standardized features of a productivity-focused mail client, including:- snooze- schedule send - undo send- read receipts/activity- gmail hotkeysThere is also a KILLER feature that most apps either don't offer, apply sporadically, or charge you an arm and a leg for: automatic email returns to your inbox if you don't get a reply. Most apps that offer this will make you manually choose for an email to be bounced back without a reply, but as a business owner I want this to happen automatically, and Polymail is the only client I've tried that offers this affordably (Mail Butler I think will do this for $50/month). It's now an essential part of my work-flow, and I feel really hamstrung without it!There are also a host of features available to teams, including Slack/Asana/Salesforce integration, team message templates, mentions, and shared comments on emails.All in all an amazing mail client. I'm really excited to see what changes and improvements are coming down the pike for them.