# Mail::Message::Field::DKIM - message header field for dkim signatures - perldoc - [phpMan]

## NAME
    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown) - message header field for dkim signatures

## INHERITANCE
     [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)
       is a [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown)
       is a [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)
       is a [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)
       is a [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

## SYNOPSIS
     my $f = [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)->new('DKIM-Signature' => '...');

     my $g = [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)->new('DKIM-Signature');
     $g->add...

## DESCRIPTION
    Decode the information contained in a DKIM header. You can also construct DKIM-Signature headers
    this way. However, verification and signing is not yet implemented.

    This implementation is based on RFC6376.

    Extends "DESCRIPTION" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown).

## OVERLOADED
    Extends "OVERLOADED" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown).

    overload: ""
        Inherited, see "OVERLOADED" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    overload: 0+
        Inherited, see "OVERLOADED" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    overload: <=>
        Inherited, see "OVERLOADED" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    overload: bool
        Inherited, see "OVERLOADED" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    overload: cmp
        Inherited, see "OVERLOADED" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    overload: stringification
        Inherited, see "OVERLOADED" in [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)

## METHODS
    Extends "METHODS" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown).

### Constructors
    Extends "Constructors" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown).

    $obj->clone()
        Inherited, see "Constructors" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->from($field, %options)
        Inherited, see "Constructors" in [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)

    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->new($data)
         -Option    --Defined in                      --Default
          attributes  [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown)  <ignored>
          charset     [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)        undef
          datum       [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown)  undef
          encoding    [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)        'q'
          force       [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)        false
          language    [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)        undef
          log         [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)                    'WARNINGS'
          trace       [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)                    'WARNINGS'

        attributes => ATTRS
        charset => STRING
        datum => STRING
        encoding => 'q'|'Q'|'b'|'B'
        force => BOOLEAN
        language => STRING
        log => LEVEL
        trace => LEVEL

### The field
    Extends "The field" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown).

    $obj->isStructured()
    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->isStructured()
        Inherited, see "The field" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->length()
        Inherited, see "The field" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->nrLines()
        Inherited, see "The field" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->print( [$fh] )
        Inherited, see "The field" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->size()
        Inherited, see "The field" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->string( [$wrap] )
        Inherited, see "The field" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->toDisclose()
        Inherited, see "The field" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

### Access to the name
    Extends "Access to the name" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown).

    $obj->Name()
        Inherited, see "Access to the name" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->name()
        Inherited, see "Access to the name" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->wellformedName( [STRING] )
        Inherited, see "Access to the name" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

### Access to the body
    Extends "Access to the body" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown).

    $obj->body()
        Inherited, see "Access to the body" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->decodedBody(%options)
        Inherited, see "Access to the body" in [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)

    $obj->folded()
        Inherited, see "Access to the body" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->foldedBody( [$body] )
        Inherited, see "Access to the body" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->stripCFWS( [STRING] )
    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->stripCFWS( [STRING] )
        Inherited, see "Access to the body" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->unfoldedBody( [$body, [$wrap]] )
        Inherited, see "Access to the body" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

### Access to the content
    Extends "Access to the content" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown).

    $obj->addAttribute(...)
        Attributes are not supported here.

    $obj->addTag($name, $value|@values)
        Add a tag to the set. When the tag already exists, it is replaced. Names are (converted to)
        lower-case. When multiple values are given, they will be concatenated with a blank (and may
        get folded there later)

    $obj->addresses()
        Inherited, see "Access to the content" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->attrPairs()
        Inherited, see "Access to the content" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown)

    $obj->attribute( $object|<STRING, %options>|<$name,$value,%options> )
        Inherited, see "Access to the content" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown)

    $obj->attributes()
        Inherited, see "Access to the content" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown)

    $obj->beautify()
        Inherited, see "Access to the content" in [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)

    $obj->comment( [STRING] )
        Inherited, see "Access to the content" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->createComment(STRING, %options)
    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->createComment(STRING, %options)
        Inherited, see "Access to the content" in [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)

    $obj->createPhrase(STRING, %options)
    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->createPhrase(STRING, %options)
        Inherited, see "Access to the content" in [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)

    $obj->study()
        Inherited, see "Access to the content" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->tag($name)
        Returns the value for the named tag.

    $obj->toDate( [$time] )
    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->toDate( [$time] )
        Inherited, see "Access to the content" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->toInt()
        Inherited, see "Access to the content" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

   DKIM-Signature tags
    The tag methods return the tag-value content without any validation or modification. For many
    situations, the actual content does not need (expensive) validation and interpretation.

    $obj->tagAgentID()
        The Agent or User Identifier (AUID). Defaults to @$domain

    $obj->tagAlgorithm()
        Signature algorithm. Should be rsa-sha(1|256): check before use. Required.

    $obj->tagBodyLength()
        The number of octets which where used to calculate the hash. By default, the whole body was
        used.

    $obj->tagC14N()
        The canonicalization method used. Defaults to 'simple/simple'.

    $obj->tagDomain()
        The sub-domain (SDID) which claims responsibility for this signature. Required.

    $obj->tagExpires()
        The timestamp when the signature will expire. Recommended.

    $obj->tagExtract()
        Some headers from the original message packed together.

    $obj->tagQueryMethods()
        A colon-separated list of method which can be used to retrieve the public key. The default
        is "dns/txt" (currently the only valid option)

    $obj->tagSelector()
        The selector subdividing the $domain tag. Required.

    $obj->tagSignData()
    $obj->tagSignature()
        Message signature in base64, with whitespaces removed. Required.

    $obj->tagSignedHeaders()
        The colon separated list of headers which need to be included in the signature. Required.

    $obj->tagTimestamp()
        When the signature was created in UNIX-like seconds (since 1970). Recommended.

    $obj->tagVersion()
        Signature header syntax version (usually 1)

### Other methods
    Extends "Other methods" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown).

    $obj->dateToTimestamp(STRING)
    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->dateToTimestamp(STRING)
        Inherited, see "Other methods" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

### Internals
    Extends "Internals" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown).

    $obj->consume( $line | <$name,<$body|$objects>> )
        Inherited, see "Internals" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->decode(STRING, %options)
    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->decode(STRING, %options)
        Inherited, see "Internals" in [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)

    $obj->defaultWrapLength( [$length] )
        Inherited, see "Internals" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->encode(STRING, %options)
        Inherited, see "Internals" in [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)

    $obj->fold( $name, $body, [$maxchars] )
    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->fold( $name, $body, [$maxchars] )
        Inherited, see "Internals" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->setWrapLength( [$length] )
        Inherited, see "Internals" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->stringifyData(STRING|ARRAY|$objects)
        Inherited, see "Internals" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

    $obj->unfold(STRING)
        Inherited, see "Internals" in [Mail::Message::Field](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField/markdown)

### Parsing
    Extends "Parsing" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown).

    $obj->consumeComment(STRING)
    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->consumeComment(STRING)
        Inherited, see "Parsing" in [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)

    $obj->consumeDotAtom(STRING)
        Inherited, see "Parsing" in [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)

    $obj->consumePhrase(STRING)
    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->consumePhrase(STRING)
        Inherited, see "Parsing" in [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)

    $obj->datum( [$value] )
        Inherited, see "Parsing" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown)

    $obj->parse(STRING)
        Inherited, see "Parsing" in [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)

    $obj->produceBody()
        Inherited, see "Parsing" in [Mail::Message::Field::Full](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AFull/markdown)

### Error handling
    Extends "Error handling" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown).

    $obj->AUTOLOAD()
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->addReport($object)
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback]
    )
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->errors()
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->log( [$level, [$strings]] )
    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->log( [$level, [$strings]] )
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->logPriority($level)
    [Mail::Message::Field::DKIM](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3ADKIM/markdown)->logPriority($level)
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->logSettings()
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->notImplemented()
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->report( [$level] )
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->reportAll( [$level] )
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->trace( [$level] )
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->warnings()
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

### Cleanup
    Extends "Cleanup" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown).

    $obj->DESTROY()
        Inherited, see "Cleanup" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

## DETAILS
    Extends "DETAILS" in [Mail::Message::Field::Structured](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AMessage%3A%3AField%3A%3AStructured/markdown).

## DIAGNOSTICS
    Warning: Field content is not numerical: $content
        The numeric value of a field is requested (for instance the "Lines" or "Content-Length"
        fields should be numerical), however the data contains weird characters.

    Error: Field name too long (max $length), in '$name'
        It is not specified in the RFCs how long a field name can be, but at least it should be a
        few characters shorter than the line wrap.

    Warning: Illegal character in charset '$charset'
        The field is created with an utf8 string which only contains data from the specified
        character set. However, that character set can never be a valid name because it contains
        characters which are not permitted.

    Warning: Illegal character in field name $name
        A new field is being created which does contain characters not permitted by the RFCs. Using
        this field in messages may break other e-mail clients or transfer agents, and therefore
        mutulate or extinguish your message.

    Warning: Illegal character in language '$lang'
        The field is created with data which is specified to be in a certain language, however, the
        name of the language cannot be valid: it contains characters which are not permitted by the
        RFCs.

    Warning: Illegal encoding '$encoding', used 'q'
        The RFCs only permit base64 ("b " or "B ") or quoted-printable ("q" or "Q") encoding. Other
        than these four options are illegal.

    Error: No attributes for DKIM headers
        Is is not possible to add attributes to this field.

    Error: Package $package does not implement $method.
        Fatal error: the specific package (or one of its superclasses) does not implement this
        method where it should. This message means that some other related classes do implement this
        method however the class at hand does not. Probably you should investigate this and probably
        inform the author of the package.

## SEE ALSO
    This module is part of Mail-Message distribution version 3.015, built on December 11, 2023.
    Website: <http://perl.overmeer.net/CPAN/>

## LICENSE
    Copyrights 2001-2023 by [Mark Overmeer <<markov@cpan.org>>]. For other contributors see ChangeLog.

    This program is free software; you can redistribute it and/or modify it under the same terms as
    Perl itself. See <http://dev.perl.org/licenses/>