How to set up email filters and an out-of-office reply in mello

Why filter on the server

A filter in a mail app only runs while that app is open, and only on that device. mello’s filters run on the server as each message arrives, whether anything is open or not.

• Everywhere at once. A message moved to a folder is in that folder on your phone, on your laptop and in the webmail.
• New mail only. Filters act on mail as it arrives. They don’t sort what is already in your mailbox: move that yourself.
• No save button. Everything on the Auto-reply tab saves as you change it.

Add a filter

Each filter is one rule: If a line of the message contains some text, Then do something.

1. Open Settings → Auto-reply and scroll down to Filters.
2. Choose Add rule, or press +.
3. After If, pick from, to or subject, and type the text it contains: an address, a domain such as @example.com, a name, or a word.
4. After Then, pick what happens: move to a folder, mark read, delete, or forward to an address.
5. For move to, pick the folder. For forward to, type the address.

The text matches anywhere in that line, and upper or lower case doesn’t matter. from matches the sender’s name as well as their address. to looks at the To line only, not at Cc. To remove a rule, choose the cross at the end of it.

To sort into a new folder, create the folder first: the menu lists only the folders you already have.

How the rules are applied

Rules run from top to bottom, on each new message.

• move to and delete end it. Once one of them matches, the rules below are skipped, so put the most specific rules first.
• mark read and forward to don’t. The message goes on through the rules below, so you can mark a message read and still move it with a later rule.
• forward to sends a copy, and keeps the message here too.
• delete removes the message for good. It doesn’t go to the Trash, and you never see it. If you only want it out of the way, use move to with the Trash or an archive folder instead.

You can have up to 50 rules.

Turn on an out-of-office reply

1. Open Settings → Auto-reply and turn on Reply automatically.
2. Check the Subject. It starts as “Out of office”: change it if you like.
3. Write your Message: how long you’re away, and who to contact in the meantime.
4. In Once per sender every … days, choose how often the same person gets it: from 1 to 30 days, 7 by default.

The reply is on as soon as the message is written. mello doesn’t turn it off on a date, so when you’re back, turn Reply automatically off yourself.

mello is careful about who gets the reply. It goes only to people who wrote to you directly, with your address in To or Cc. It never goes to mailing lists and newsletters, to automatic senders such as no-reply addresses, or to mail marked as spam. Blocked senders don’t get it either.

Forward all your mail

On the same tab, Forward my mail sends every incoming message on to another address, for example while you try mello alongside an old account.

1. Turn on Forward my mail.
2. Type the address in Forward to.
3. Leave Keep a copy here on to keep the messages in mello as well. Turn it off, and they only go on, without being filtered here.

Mail the spam filter caught isn’t forwarded: it stays in your Junk folder.

Block a sender

Mail from a blocked sender goes straight to the Trash. They aren’t told, they get no auto-reply, and their mail is never forwarded.

1. Open a message from them, open the more menu, and choose Block followed by their name. That message moves to the Trash too.
2. Or open Settings → Auto-reply → Blocked senders, type an address, or @ and a domain to block a whole domain (@example.com), and choose Block.

To unblock someone, choose the cross next to them in the list. Their next messages arrive as usual; anything already in the Trash you move back yourself.

Blocking goes by the sender’s address. For spam that keeps changing address, use Report spam instead.

For power users: your own Sieve script

The settings page writes a Sieve script (RFC 5228) for you. If you want tests it doesn’t offer, such as several conditions at once, any header, or the message size, write your own and upload it with a ManageSieve client, for example the Sieve add-on for Thunderbird.

The password is your mello password. A few things to know first:

• Supported extensions: fileinto, envelope, copy, imap4flags and vacation. A script that requires any other, such as regex, body or include, is refused when you upload it. So a script can’t look at the message body.
• One script runs at a time. The webmail’s own is called webmail. When you make yours the active one, the webmail’s rules, auto-reply, forwarding and blocked senders stop running.
• The webmail takes over again when you save there. Changing the Auto-reply tab, the newsletter digest or your language, or blocking a sender from a message, makes webmail the active script again. Copy what you need from it into your own, and keep your changes in one place.
• Don’t edit the webmail script by hand. The settings page rewrites it every time it saves.
• Limits: up to 10 scripts, of up to 64 KB each.

What mello can’t do yet

• No dates for the auto-reply. Turn it on when you leave and off when you’re back.
• Simple tests in the editor. One condition per rule (from, to or subject contains), with no “all of these” or “any of these”. Your own Sieve script can do more, within the extensions above.
• Filters aren’t in the CLI or the assistant. You set them in the webmail or with a ManageSieve client. The mello CLI and the assistant connector don’t change them.
• Existing mail isn’t sorted. A new rule acts on mail that arrives after you add it.

For newsletters, there’s a gentler option than a filter: the daily digest, in Settings → Notifications. See newsletters and subscriptions.