Sieve Vacation Extension: Save Out of Office Replies

Question

I have an SMTP + IMAP server on linux and use sieve filtering to provide some useful features.

One such feature is out-of-office replies, provided by the following script:

require ["fileinto", "vacation", "variables"];

# ignore spam
if header :contains "X-Spam-Flag" "YES" {
  fileinto "Junk E-mail";
  stop;
}

vacation
  :days 1
  :subject "Out of office"
  :addresses ["..."]
"contact x, y, or z instead.";

However, I don't like the fact that the auto-replies are transparent to the user; there is no way for a user to definitively answer the question "did X receive a reply?". I would also prefer users, on principle, to be able to see every email that is sent from their address.

For this reason, I would like to store all out-of-office replies in the users sent folder. This way, users can easily review the automatic replies that have been sent.

Does anyone know how this could be achieved?

And you believe users will check their sent mail folder for this? Good luck with that. — Sven, Apr 29 '19 at 12:49
@Sven It's a small office, so training behaviour isn't such a problem. Besides, i think it's a fair principle that sent mail should include automatic replies from that address. — , Apr 29 '19 at 12:54
@Sven I modified the question to better explain my motivation. — , Apr 29 '19 at 13:08

score 0 · Answer 1 · answered Apr 19 '23 at 22:32

There is no straightforward way to achieve your objective because Sieve scripts are run on the incoming mail only. Outgoing messages are processed by Postfix/Exim/Sendmail or whatever mail transfer agent you are using and therefore Sieve does not get involved. For incoming messages, RFC 5230 expressly prohibits using vacation together with Sieve's "fileinto" action: see section 4.7 of RFC 5230.

So, for Sieve to get involved (1) you must send a copy of your outgoing vacation message to yourself, and (2) you must provide a way for Sieve to identify your vacation auto-reply so that it can move the incoming auto-reply message to your Sent folder.

One possible way to make it happen is through the use of the "plus-aliasing" mechanism in Postfix. This way, you can send vacation auto-replies from the "plus-alias" address and thus identify them for both Postfix and Dovecot/Sieve.

In your Sieve script, make sure that vacation auto-replies are sent from your "plus-alias" address:

vacation
  :from "Your Name <your.name+ooor@example.com>"

Add the following to /etc/postfix/main.cf:

recipient_delimiter = +
header_checks = pcre:/etc/postfix/header_checks.pcre

In /etc/postfix/header_checks.pcre, identify your outgoing vacation messages and add a rule to copy such messages to yourself:

/^From: [^<]*<your.name\+ooor@example.com>/  BCC your.name@example.com

It may be possible to use backreferences to write a general rule like From: [^<]*<([^\+]+)\+ooor@example.com>/ BCC $1@example.com, but I have not tried it and cannot say whether this works or not.

Make sure that you have recipient_delimiter = + in /etc/dovecot/conf.d/90-sieve.conf (or whatever other file you are using to configure Sieve).

Finally, add the following rule to the top of your Sieve vacation script:

require ["vacation", "variables", "date", "relational", "fileinto", "envelope"];
if allof ( address :is :all "from" "your.name+ooor@example.com",
           envelope :is :all "to" "your.name@example.com" ) {
  fileinto "Sent";
}

This Sieve rule will move messages addressed to you and originating from your.name+ooor@example.com to your Sent folder.

Sieve Vacation Extension: Save Out of Office Replies

1 Answers1