Mail rules,
managed on mobile.

Your Outlook rules run on the server, filing and forwarding mail whether or not anything is open. Rulebook lets you read them, spot the broken ones and write new ones — from your phone.

View on GitHub Support

What it does

Rulebook talks to the rules already on your Microsoft 365 mailbox. It doesn't run its own filtering, and nothing stops working when you close it.

Read what's actually running

Every rule in evaluation order, in plain words, with folder names instead of opaque identifiers.

Find the broken ones

Outlook reports a rule as healthy even when it files into a folder that no longer exists. Rulebook checks that itself.

Write new rules

Conditions, exceptions and actions, offering only what your provider can actually express.

Reorder and disable

Order decides which rule wins. Drag to change it, or switch a rule off without deleting it.

The rule that looks fine and isn't

A rule pointing at a folder you deleted keeps its green light. Exchange reports it as healthy; mail matching it quietly stops arriving where you expect. The only symptom is mail you never see.

Rulebook resolves every destination against your real folder list, and flags rules that can never run because an earlier rule already stopped processing. Both checks happen on the phone, against what the server actually returns.

On the mailbox this was first tested against, two of six rules pointed at deleted folders. Outlook had flagged only one of them.

What it asks for, and why

Sign-in goes through Microsoft's own page. Rulebook never sees your password, and the access it gets can be revoked at any time from your account settings.

PermissionWhy
MailboxSettings.ReadWrite Read and write the rules themselves. This is the app.
Mail.ReadBasic List your folders, so a rule can file mail into one you already have.
offline_access Stay signed in without asking again every time.

Mail.ReadBasic is broader than this app wants: it also grants the sender, recipients and subject of your messages. The precise permission for reading folders alone — MailboxFolder.Read — exists, but only for work and school accounts, so an app that also serves personal Microsoft accounts cannot request it. That trade is spelled out here rather than buried.

Rulebook does not read message bodies, does not send mail, and stores no mail of its own.

Status

In development, and open source. Microsoft 365 and Outlook.com work today; Gmail's translation layer is written and tested but its client isn't finished yet.

There is also a command-line tool in the repository that talks to the same engine — useful for inspecting rules, checking which of them would survive a move to another provider, and seeing exactly what gets sent.