I'd like to run rules on emails that already exist. Not just on new ones. That way I can lable all old emails that meet a certain criteria.

Most email apps I've used me to drag and drop files from the app straight into another app or website. So I'd expect a file can be pulled from Missive, for example, and dropped straight into an upload prompt on Dropbox or WordPress website. In the current version, however, drag and drop only works from Missive to Finder. Drag it anywhere else and the other app doesn't recognize that I'm trying to drop a file on it. So I have to drag from Missive to Finder, then grab and drag from Finder to the app I need the file in, then go back and delete the app out of Finder because I didn't really need it there in the first place. Would love to eliminate all of those extra steps :D

Measure performance metrics like response time and message volume for more data-driven decisions thanks to users statistics.

Would love to see a one click unsubscribe feature that can be seen in polymail, etc.

Quite often I miss the attached file or I have to scroll way down in a long email thread.

Start email with "Hey first_name" on tab or even better if it adapts to language in the email you are responding to.

As a team communication tool, it'd be helpful to see when my teammate has read my chat message. Not sure how this scales to many teammates, maybe similar to a group Messenger conversation? (showing people's faces at the last message they've read)

Hi, It could be a great to allow search a text in a specific thread and allow navigation from all occurrences of this text in this thread's different emails, collapsed or not. Thanks in advance for that

Please integrate Apple Calendar

When typing URLs like calendar.google.com into the body of an email, that URL does not automatically turn into a Hyperlink like it does in some email clients. It would be great to have subdomains like that automatically turned into clickable hyperlinks.