Adding a “sync new mail” button after the “compose new email” button would be nice.
(Originally posted by algkmn on GitHub.)
For the same effect you can push F5, I don’t know if you know.
(Originally posted by dtokarczyk on GitHub.)
Hey! Thanks for filing this! Honestly, we probably won’t implement this because for (almost all) mail providers, Mailspring holds an IMAP IDLE connection open to your mail server and the app is notified of mailbox changes, so choosing “Sync New Mail” doesn’t really make a difference in most scenarios. (It does kick off a forced resync of all your folders, but typically the new mail would have arrived in the same amount of time without any user action.)
We will be putting a calendar icon up there soon though! 
(Originally posted by bengotow on GitHub.)
Pressing the refresh button makes my brain happy, even if it doesn’t technically do anything. Having it not there would feel wrong, as every other email client has one.
(Originally posted by c-bandy on GitHub.)
As far as I know, IMAP IDLE only allows one folder per connection. Does Mailspring open multiple connections to the IMAP server (one per folder), or does it only use IMAP IDLE for the main inbox?