Using Sieve Scripts

Sieve is a language for filtering e-mails. It is used to add complex rules that cannot be added via the filtering rules.

The final script is stored in the /home/[account]/admin/mail/[domain]/[box]/filter_user.sieve file in your account. You can read it to help debug your script, but you cannot edit it.

Extensions supported

Extension	Description
body	Checks the presence of one or more character strings in the e-mail message body
comparator-i;ascii-numeric	Extracts numbers from the text and compares them to see if it matches
copy	Specifies that a copy should be used to perform the action
date	Performs actions based on the date/time when an e-mail is sent/received
duplicate	Detects whether it is a duplicate
editheader	Adds or deletes text in the headers
encoded-character	Allows encoding special characters
enotify	Sends notifications
envelope	Assesses the envelope ("from", "to", etc.)
environment	Tests different labeled values in the execution environment
fileinto	Delivers the e-mail to the specified folder
foreverypart	Allows commands to be run in all MIME parts of the e-mail
ihave	Tests whether a Sieve extension is available and, if so, executes its action
imap4flags	Adds IMAP indicators and key words to messages
include	Used to include a Sieve script in another one
index	Used to match specific header fields by index
mailbox	Checks whether a specific directory exists
mime	Tests the specific MIME parts in the message
extracttext	Extracts text from MIME parts
regex	Uses regular expressions
reject	Refuses message delivery
relational	Allows relational comparisons
subaddress	Tests bounded elements in the location part of the addresses
vacation	Automatic answering
variables	Used to add variables

Examples

Add a <SPAM> prefix to the subject of an e-mail comprising a key word to define (whether in the subject or in the body text)

require ["editheader", "variables", "body"] ;
if allof (
header :contains "subject" "word",
header :matches "Subject" "*"
)
{
deleteheader "Subject";
addheader "Subject" "<SPAM> ${1}";
}
elsif allof (
body :content "text" :contains "word",
header :matches "Subject" "*"
)
{
deleteheader "Subject";
addheader "Subject" "<SPAM> ${1}";
}

Use headers in variables for automatic responses

require ["variables", "vacation"];

# Store subject header in variable
if header :matches "Subject" "*" {
        set "subj" "**${1}**";
}

# Auto-reply
vacation
  :days 1
  :subject "Out-of-office [Was: ${subj}]"
"Hello,
We've received your last message:

${subj}

We're currently out-of-office and will reply soon.";

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Links

• RFC 5228