Built-in Tests (GNU Mailutils Manual)

5.6.1 Built-in Tests

Test: false: This test always evaluates to “false”.

Test: true: This test always evaluates to “true”.

Test: address [address-part] [comparator] [match-type] header-names key-list

Tagged arguments:

address-part: Selects the address part to compare. Default is the whole email address (:all).
comparator: Specifies the comparator to be used instead of the default i;ascii-casemap.
match-type: Specifies the match type to be used instead of the default :is.

Required arguments:

header-names: A list of header names.
key-list: A list of address values.

The address test matches Internet addresses in structured headers that contain addresses. It returns true if any header contains any key in the specified part of the address, as modified by comparator and match-type optional arguments.

This test returns true if any combination of the header-names and key-list arguments match.

The address primitive never acts on the phrase part of an email address, nor on comments within that address. Use the header test instead. It also never acts on group names, although it does act on the addresses within the group construct.

Example:

if address :is :all "from" "tim@example.com"
  {
     discard;
  }

Test: size [:over | :under] limit(number)

The size test deals with the size of a message. The required argument limit represents the size of the message in bytes. It may be suffixed with the following quantifiers:

‘k’
‘K’: The number is expressed in kilobytes.
‘m’
‘M’: The number is expressed in megabytes.
‘g’
‘G’: The number is expressed in gigabytes.

If the tagged argument is ‘:over’, and the size of the message is greater than number, the test is true; otherwise, it is false.

If the argument is ‘:under’, and the size of the message is less than the number, the test is true; otherwise, it is false.

Otherwise, the test is true only if the size of the message equals exactly number. This is a GNU extension.

The size of a message is defined to be the number of octets from the initial header until the last character in the message body.

Test: envelope [address-part] [comparator] [match-type] envelope-part(string-list) key-list(string-list)

Tagged arguments:

address-part: Selects the address part to compare. Default is the whole email address (:all).
comparator: Specifies the comparator to be used instead of the default i;ascii-casemap.
match-type: Specifies the match type to be used instead of the default :is.

Required arguments:

envelope-parts: A list of envelope parts to operate upon.
key-list: A list of address values.

The envelope test is true if the specified part of the SMTP envelope matches the specified key.

If the envelope-part strings is (case insensitive) ‘from’, then matching occurs against the FROM address used in the SMTP MAIL command.

Notice, that due to the limitations imposed by SMTP envelope structure the use of any other values in envelope-parts header is meaningless.

Test: exists header-names(string-list)

Required arguments:

header-names: List of message header names.

The exists test is true if the headers listed in header-names argument exist within the message. All of the headers must exist or the test is false.

The following example throws out mail that doesn’t have a From header and a Date header:

if not exists ["From","Date"]
  {
     discard;
  }

Test: header [comparator] [match-type] [:mime] header-names(string-list) key-list(string-list)

Tagged arguments:

comparator: Specifies the comparator to be used instead of the default i;ascii-casemap.
match-type: Specifies the match type to be used instead of the default :is.
:mime: This tag instructs header to search through the mime headers in multipart messages as well.

Required arguments:

header-names: A list of header names.
key-list: A list of header values.

The header test evaluates to true if any header name matches any key. The type of match is specified by the optional match argument, which defaults to ":is" if not explicitly given.

The test returns true if any combination of the header-names and key-list arguments match.

If a header listed in header-names exists, it contains the null key (‘""’). However, if the named header is not present, it does not contain the null key. So if a message contained the header

X-Caffeine: C8H10N4O2

these tests on that header evaluate as follows:

header :is ["X-Caffeine"] [""] ⇒ false
header :contains ["X-Caffeine"] [""] ⇒ true

This document was generated on January 2, 2022 using makeinfo.

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GNU Mailutils

General-Purpose Mail Package

5.6.1 Built-in Tests