Can I reorder account sub-mailboxes in the sidebar?
Missive does not offer a way to manually reorder email accounts, but you can customize the description of each account in your Accounts settings, as shown here:
Email accounts are listed in alphabetical order, so if you want to reorder them in a certain way, you can simply enter descriptions that start with a number:
1 - [Description for account 1]
2 - [Description for account 2]
3 - [Description for account 3]