Hello, the email takes very long to update push or show new emails and there is no easy setting to force it when expecting code like OTP
There is a manual trigger, though it’s not very discoverable: press F5, or choose File > Sync New Mail Now from the menu. That tells the sync engine to check every account immediately, which is what you want when you’re waiting on an OTP code.
As for why it’s slow in the first place: Mailspring gets instant delivery through IMAP IDLE, where the server pushes a notification the moment a message lands. If your provider doesn’t support IDLE (or drops idle connections quickly), new mail only shows up on the next periodic check. If you tell me which provider this is, I can check whether that’s the case, and the account’s sync log (Preferences > Accounts > select the account > Error Details…) will show whether IDLE is being used or repeatedly failing.