Sieve filters

Mails can be redirect to specific channels or users by using sieve filtering language. If you want to send the message to a specific channel (even a private channel), use the fileinto sieve command, if you want to redirect the message to a specific user, use the redirect sieve command. You can also silently discard the mail by using the discard sieve command.

Note

if no rules match the mail, the default command is to keep the mail which will be send to the default_channel.

Note

channels must be lower case, without non-ascii characters (remove them if any) and spaces replaced by hyphens -.

Note

sieve standard requires that files are in dos specification ending lines (CRLF or \r\r). For information, Mac ending lines are CR (or \r) and unix ending lines are LF (or \n).

Commands

keep

In m2mb the keep command means to send the message to the default channel.

In sieve standard, there is an implicit keep which will apply if no rules match. You can also explicitly use the keep command to say that you want these mails to be send to the default channel.

fileinto

In m2mb the fileinto command is used to send the message to a specific channel. The channel must exists (or the sending will silently fail).

redirect

In m2mb the redirect command is used to send the message to a specific user. You can provide the username with or without the leading @.

stop

The stop command will stop further processing of the sieve rules. Can be useful to explicitly stop processing of rules after a discard, redirect or fileinto statement.

Examples

Exemple 1

The following example will send all mails containing the word private in their subject field into the private channel. If the mail does not contains the word private in the subject the filter test if the mail is destinated to a mail address containing user1 or user2 and will send a direct message to the corresponding user. If none of the previous rules match, the message will be send to the default channel.

require "fileinto";

    if header :contains "Subject" ["private"] {
            fileinto "private";
            stop;
    } else {
            if address :contains "To" "user1" {
                    redirect "user1";
            } elsif address :contains "To" "user2" {
                    redirect "@user2";
            }
    }

Example 2

If you want to discard non matching mails, you can add a discard statement at the end of the file. You should also add stop statements after all other commands otherwise the discard statement will also be interpreted (this has an undefined behaviour in this implementation).

require "fileinto";

    if header :contains "Subject" ["private"] {
            fileinto "private";
            stop;
    } else {
            if address :contains "To" "user1" {
                    redirect "user1";
        stop;
            } elsif address :contains "To" "user2" {
                    redirect "@user2";
        stop;
            }
    }
discard;