Sieve Extension: File Carbon Copy (Fcc)
draft-ietf-extra-sieve-fcc-00

Abstract

The Sieve Email Filtering Language consists of action commands that can reply to the sender of an incoming message with a generated message. This document defines an extension to such commands to allow a copy of the generated reply message to be filed into a target mailbox.

Open Issues

• Should :fcc be allowed with reject/ereject?
• Should there be a separate capability string for each action that uses :fcc (e.g. "vacation-fcc")?

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on March 25, 2018.

Copyright Notice

Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved.

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Table of Contents

• 1. Introduction
• 2. Conventions Used in This Document
• 3. The ":fcc" Argument
• 3.1. Interaction with Fileinto Extensions
• 3.1.1. Imap4flags Extension
• 3.1.2. Mailbox Extension
• 3.1.3. Special-Use Extension
• 3.1.4. Extended Example
• 4. Security Considerations
• 5. IANA Considerations
• 6. References
• 6.1. Normative References
• 6.2. Informative References
• Authors' Addresses

1. Introduction

The Sieve Email Filtering Language consists of action commands that can reply to the sender of an incoming message with a generated message. Three such commands are defined by the Vacation Extension and the Reject and Extended Reject Extensions. It is sometimes desirable to have an archive of these auto-generated reply messages.

This extension defines a ":fcc" argument to action commands which generate reply messages to allow a copy of the reply message to be filed into a target mailbox.

The capability string associated with this extension is "fcc".

2. Conventions Used in This Document

Conventions for notations are as in Section 1.1 of [RFC5228], including use of the "Usage:" label for the definition of action and tagged arguments syntax.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

3. The ":fcc" Argument

Usage:   ":fcc" FCC-OPTIONS <mailbox: string>

The positional FCC-OPTIONS argument is defined here in ABNF syntax so that it can be modified by other extensions.

FCC-OPTIONS = ""  ; empty string

If the optional ":fcc" argument is specified with an action that generates a reply message, it instructs the Sieve interpreter to file a copy of the message into the target mailbox. If the specified mailbox doesn't exist, the implementation MAY treat it as an error, create the mailbox, or file the message into an implementation-defined mailbox.

Example:

require ["reject", "fcc"];

if header :contains "Subject" "Make Money Fast" {
    reject :fcc "Junk" "Your message is considered junk email.";
}

3.1. Interaction with Fileinto Extensions

The "fcc" extension can be used with some tagged arguments defined in extensions to the "fileinto" action. The sections below describe its interaction with currently defined extensions. Tagged arguments in future extensions to the "fileinto" command should describe their use with ":fcc", if any.

3.1.1. Imap4flags Extension

This document extends the definition of the ":flags" tagged argument so that it can be used as an FCC-OPTIONS to the ":fcc" argument.

FCC-OPTIONS =/ [":flags" <list-of-flags: string-list>]

If the optional ":flags" argument is specified with ":fcc", it instructs the Sieve interpreter to set the IMAP4 flags provided in the subsequent argument when the the reply message is filed into the target mailbox.

3.1.2. Mailbox Extension

This document extends the definition of the ":create" tagged argument so that it can be used as an FCC-OPTIONS to the ":fcc" argument.

FCC-OPTIONS =/ [":create"]

If the optional ":create" argument is specified with ":fcc", it instructs the Sieve interpreter to create the target mailbox, if needed, before attempting to file the reply message into the target mailbox.

3.1.3. Special-Use Extension

This document extends the definition of the ":specialuse" tagged argument so that it can be used as an FCC-OPTIONS to the ":fcc" argument.

FCC-OPTIONS =/ [":specialuse <special-use-flag: string>"]

If the optional ":specialuse" argument is specified with ":fcc", it instructs the Sieve interpreter to check whether a mailbox exists with the specific special-use flag assigned to it. If such a mailbox exists, the reply message is filed into the special-use mailbox. Otherwise, the reply message is filed into the target mailbox.

If both the optional ":specialuse" and ":create" arguments are specified with ":fcc", the Sieve interpreter is instructed to create the target mailbox per Section 4.1 of [I-D.ietf-extra-sieve-special-use], if needed.

3.1.4. Extended Example

require ["vacation", "fcc", "mailbox", "special-use", "imap4flags"];

vacation :days 7
         :fcc :specialuse "\\Sent" :create :flags ["\\Seen"] "INBOX.Sent"
         :from "hemingway@example.com" "Gone Fishin';

4. Security Considerations

The "fcc" extension does not raise any other security considerations that are not already present in [RFC5228], [RFC5429], [RFC5230], and [RFC6131].

5. IANA Considerations

6. References

6.1. Normative References

6.2. Informative References

Authors' Addresses