Preview PDF and Word, Excel, Powerpoint documents
I love how Gmail and other web applications allow you to click an attachment to preview WITHOUT downloading the document. This is particularly useful for Microsoft documents, since the Microsoft applications take forever to open.
Download e-mail or whole thread in PDF
It would be very useful to be able instead of "print -> select printer -> generate PDF" etc to simply select Download as PDF (just as it is possible to download as eml) . Simply one click solution :)
View all attachments in the conversation / email thread
Front has a similar feature when you click on the information icon. It lets you preview all attachments in the email thread and download them instead of searching for them through emails. It is very useful as we send clients a lot of PDF documents and it would be great to se them all in one place.
Solo paid plan
I would love a 'solo' plan that is somewhere between the two paid plans you already have, which allows for solo usage only, thus fitting freelancers like me best. I am a bit turned away by the price of the unlimited plan and wouldn't need the team features at all, but would love to see all my e-mail instead of only recent mail.
Show calendar availability of coworkers when scheduling event
In Google Calendar it's possible to view the calendars of coworkers, so that it's easy to make an appointment. It would be really cool, if this is also possible in Missive.
Ignore invite.ics files when searching for attachments
I know that search results are provided by the mail provider (like Gmail). Still searching emails for attachments outputs a lot of results with invite.ics files, so calendar invites. It would be great to exclude those from the results in some way.
Sort conversations by Unread, Pinned or Starred
Like we can do in gmail, will be nice the ability to sort conversations like this. Starred Emails Pinned Emails Unread Emails Rest of emails Something like this will allow have important things always in view without changing inbox or filter in sidebar.
Download emails locally for offline access
ability to download mails locally like outlook for easily offline browsing.