Short answers.

What do I need to connect?

Your email address and an app password from your provider's security page — not your normal password. The app fills in the server and keeps the password in your Mac's Keychain.

It says "LOGIN failed".

Usually a normal password was pasted instead of an app password, or the app password was revoked. Make a fresh one and paste it in. Outlook, Hotmail and Microsoft 365 are not supported yet: Microsoft only allows OAuth sign-in for this now.

Why does it need a model key?

The reading is done by Jev, billed to you at cost: at 3,040 tokens a message, that is a little over a cent per hundred messages. Your mail goes straight to them with your key, never through us. The sample inbox needs no key.

What happens after fourteen days?

Your own mailbox needs a licence; the sample inbox stays free forever. The trial starts at your first real run, not at install. Price and licence.

The mail server could not be reached.

Check the address and that IMAP is on with your provider. Save & test in Settings shows what the server said, which usually shows which part is wrong.

It filed something in the wrong place.

Press Undo on that message or the whole run. Then correct it: a few corrections of the same kind move its line, or become a rule for that sender that you can read and edit.

It stopped in the middle of a run.

Nothing is lost. Every decision is written down as it is made, so the next run carries on from where it stopped and never files a message twice.

"The mailbox changed underneath the run."

Another device moved mail at the same moment. If the mailbox itself was replaced, the app stops rather than guess; otherwise it simply tries again.

An attachment was not read.

Images are not read yet, and it says so instead of guessing. A message whose only content is an unreadable file is held for you, not filed.

It is not running on its own.

Sorting on a timer is switched on with one Terminal command for now. It stays silent unless something needs you, and if a run fails it tells you once rather than every time.

node triage.mjs --install-schedule --every 900

Can it work inside my mail app?

Thunderbird: yes, with an add-on that asks the app, so undo still works. It is a preview. Mail.app: not yet — Apple's only route runs through the App Store, which would break how the app works.

Does it work on my phone?

Nothing of it runs on a phone. It sorts on your Mac, and your phone shows the sorted mailbox. If a phone is all you use, it is not for you yet.