MailRules vs Apple Mail rules
Apple gives you two rule systems: rules in Mail on your Mac, and simpler rules in iCloud Mail settings on iCloud.com. Both match exact text. MailRules runs on its own, on the server, and understands rules written as sentences.
| MailRules | Apple Mail rules | |
|---|---|---|
| Where rules run | On the server it runs on, watching your mailbox with IMAP IDLE. Your Mac can be asleep or off. | Mac rules run in the Mail app; Apple says rules can auto-reply or forward when Mail is open. iCloud.com rules run on iCloud's servers, and changes can take up to 15 minutes to apply. |
| How rules are written | Type or dictate a sentence such as "receipts, but not shipping updates". MailRules turns it into a rule and can add exact conditions: sender, domain, subject, any header, attachments. | Pick a field, a test and a value from menus. Mac rules can match any or all conditions and use custom headers. iCloud.com rules use a single pop-up menu and text field per rule. |
| What a rule can do | Move, archive, trash, mark as junk, flag, mark read or unread, or keep. | Mac rules can move, delete, highlight, reply, forward or run an AppleScript. iCloud.com rules take one action chosen from a pop-up menu or field. |
| Which mailboxes | Any IMAP mailbox with an app password: iCloud, Fastmail, Yahoo, Zoho, Gmail or your own server. | Mac rules work on every account in Mail on that Mac. iCloud.com rules work on iCloud Mail only. |
| When it's unsure | Below your confidence threshold, the email stays in your inbox and waits in Needs review. | A rule either matches the text or it doesn't. |
| Undo | Every action shows a one-line reason and can be undone for 30 days, one email at a time or the last hour at once. Trash goes to a MailRules Trash folder first. | Apple's guides don't describe a history or undo for rule actions. |
| Price | Self-hosting is free; you pay your model provider. Hosted cloud is coming: Personal $5 a month, Pro $10 a month, Team $8 per seat. | Free with a Mac or an iCloud account. |
Rules that need Mail to be open
Rules you make in Mail on your Mac belong to that Mac’s Mail app. Apple’s own guide says rules can reply to or forward messages when Mail is open. If you read mail on your iPhone while your Mac is asleep, the inbox you see hasn’t been sorted yet. MailRules runs as a small server process. It watches your mailbox with IMAP IDLE and files new mail seconds after it lands, whether your Mac is on or not.
iCloud.com rules: on the server, but simple
iCloud Mail also has rules in its settings on iCloud.com. They run on Apple’s servers, and you can have up to 500 of them. Each one picks a message test from a pop-up menu and an action, and changes can take up to 15 minutes to apply. They only see iCloud Mail. MailRules also works on the server, and it works with any IMAP mailbox, not just iCloud.
Exact text versus what you mean
Both kinds of Apple rule match exact text: a sender, a word in the subject, a header. That works for one sender. It doesn’t work for “order confirmations from any shop” or “recruiters I haven’t replied to”. In MailRules you write that sentence. It checks senders you’ve corrected and any exact conditions first, then asks a small model only when it needs to. Anything it’s unsure of stays in your inbox for you to decide.
When Apple Mail rules is the better pick
Stay with Apple's rules if your sorting is by sender or exact subject and your Mac is usually on with Mail open. Mac rules can do things MailRules can't: reply, forward, highlight or run an AppleScript. iCloud.com rules run on the server at no cost and need nothing installed. If those cover your inbox, you don't need anything else.
Questions
Do Apple Mail rules work when my Mac is off?
Rules in the Mail app run in that app on your Mac. Rules set in iCloud Mail settings on iCloud.com run on Apple's servers, but they only cover iCloud Mail and have fewer options.
Can MailRules sort my iCloud Mail?
Yes. It connects to iCloud with an app-specific password and moves mail on the server, so Mail on your Mac, iPhone and iCloud.com all see the same folders.
Should I turn off my Apple rules first?
Not necessarily, but two systems moving the same mail is hard to follow. MailRules starts in dry-run mode, so you can compare what it would do before you switch anything off.
Can MailRules reply to or forward email like a Mac rule?
No. MailRules only files mail and never sends anything.
Do I need to write a rule for every sender?
No. A rule like "newsletters I never open" covers senders you haven't seen yet. You can still pin a sender to a rule when you want an exact match.