Why not everyone gets your out-of-office reply

Your out-of-office reply is on, but a customer says they didn't get a response. Or someone got it the first time but not after that. Usually that's not a fault: an out-of-office reply deliberately doesn't respond to every email. In this article you'll read why, and how to set it up so the right people do get a reply.

How it works

The out-of-office reply you set up in webmail under Settings > Out of Office is technically a filter on the mail server. It runs the moment mail comes in, so also when your computer is switched off. The rules for this kind of automatic reply are in the standard for Sieve vacation responses, RFC 5230. It contains a few restrictions that stop an out-of-office reply from doing harm.

1. One reply per sender per interval

The server remembers who it has already replied to. Within the How often send messages interval, the same sender doesn't get a second reply. If you don't choose anything yourself, the standard sets this to 7 days. So if someone emails you four times in three days, they get one out-of-office reply. Only after the interval do they get another one, as a reminder that you're still away.

Did you test your out-of-office reply by emailing yourself from another address? Then you won't get a reply on the second test. That means it's working.

2. No reply to mailing lists and automated mail

An out-of-office reply that responds to a mailing list with a thousand members, or two automated messages endlessly replying to each other: nobody wants that. That's why, following RFC 5230 (section 4.6), the server doesn't reply to:

• mail with a List-Id header or other List headers: newsletters and mailing lists;
• mail with an Auto-Submitted header with a value other than no: automated messages, such as another out-of-office reply or a system notification;
• mail from addresses like MAILER-DAEMON, or from addresses that start with owner- or end with -request.

Your own reply gets the header Auto-Submitted: auto-replied added to it. That way another out-of-office reply knows it shouldn't reply back. The reply also goes to the envelope sender (Return-Path). For normal mail that's the sender's address; for systems it's often a technical address.

3. Only if the mail is really addressed to you

The server only replies if one of your addresses is in the To or Cc header. This prevents replies to mail that came in via a list or as Bcc. The server knows your own mailbox address, but not an address like info@example.com that is forwarded to your mailbox.

That's why the My additional e-mail address(es) field is important:

1. Go to Settings > Out of Office and open Advanced settings.
2. Under My additional e-mail address(es), add every address you receive mail on, including aliases and forwarders. With Fill with all my addresses, webmail copies the addresses from your identities.
3. Click Save.

If you forget info@, a customer who emails info@ won't get an out-of-office reply, and may be waiting for an answer in vain.

4. Outside the start and end time

If you've filled in a Vacation start and a Vacation end, the out-of-office reply does nothing outside that period. Check that the dates are correct, including the year. If you leave them empty, the message is active as long as Status is set to On. A start and end date is the safest choice though: that way you can't forget to switch the message off.

Quickly checking why someone didn't get a reply

Leave Incoming message action set to Keep. That way incoming mail simply stays in your mailbox and you can read it when you're back.

The steps with screenshots are in the Roundcube manual under Setting up an out-of-office reply. If you use DirectAdmin, see Vacation Messages in the DirectAdmin manual.