Mail::M...::Nested(3)

📦

version 4.04 · 11 versions

💖 Mail::Message::Body::Nested 💖

okay so bestie, gather round, because this is the manual page for Mail::Message::Body::Nested — yes that's the one your shell is calling Mail::M...::Nested(3), from the User Contributed Perl Documentation set. it's the body of a message that contains another whole message. nesting dolls but make it email 🪆✨

✨ NAME ✨

Mail::Message::Body::Nested — body of a message which contains a message 💌

👑 INHERITANCE 👑

Mail::Message::Body::Nested
  is a Mail::Message::Body
  is a Mail::Reporter

  Mail::Message::Body also extends Mail::Reporter
  is a Mail::Reporter

🎀 SYNOPSIS 🎀

See Mail::Message::Body

if($body->isNested) {
   my $nest = $body->nested;
   $nest->delete;
}

🌸 DESCRIPTION 🌸

so the body (aka the content) of a message can be stored in various ways, and this page is all about the extra functionality you get when a message contains a nested message, like message/rfc822. it's giving message-ception, no cap 💅

now, a nested message is not the same as a multipart message that contains only one element, bestie — because a nested message has a full set of message header fields, as defined by the RFC882, whereas a part of a multipart has only a few. but because we do not keep track whether all fields are presented, a Mail::Message::Part is used anyway. the way that we just. don't check. iconic honestly 🙈

WARNING: Since 2023, at least outlook started to interpret RFC6533 incorrectly. Bodies of type 'message/rfc822' can only be 'nested', but when they (illegally) have Content-Transfer-Encoding, they can now behave like normal message parts (the same as a pdf or image). 😭 not them breaking the rules and then just getting away with it

Extends "DESCRIPTION" in Mail::Message::Body.

🦋 OVERLOADED 🦋

Extends "OVERLOADED" in Mail::Message::Body.

overload: '""' stringification — Inherited, see "OVERLOADED" in Mail::Message::Body
overload: '==' numerical comparison — Inherited, see "OVERLOADED" in Mail::Message::Body
overload: '@{}' addressed as array — Inherited, see "OVERLOADED" in Mail::Message::Body
overload: bool true/false — Inherited, see "OVERLOADED" in Mail::Message::Body

💜 METHODS 💜

Extends "METHODS" in Mail::Message::Body.

🧚 Constructors

Extends "Constructors" in Mail::Message::Body.

$obj->clone() — Inherited, see "Constructors" in Mail::Message::Body
$class->new(%options) — Inherited, see "Constructors" in Mail::Message::Body

here's the whole options table, verbatim, because we are not skipping a single one of these:

 -Option           --Defined in         --Default
  based_on           Mail::Message::Body  undef
  charset            Mail::Message::Body  'PERL'
  checked            Mail::Message::Body  false
  content_id         Mail::Message::Body  undef
  data               Mail::Message::Body  undef
  description        Mail::Message::Body  undef
  disposition        Mail::Message::Body  undef
  eol                Mail::Message::Body  'NATIVE'
  file               Mail::Message::Body  undef
  filename           Mail::Message::Body  undef
  language           Mail::Message::Body  undef
  message            Mail::Message::Body  undef
  mime_type          Mail::Message::Body  'message/rfc822'
  modified           Mail::Message::Body  false
  nested                                  undef
  transfer_encoding  Mail::Message::Body  'none'

and now each one, one by one, because every single detail matters fr fr:

based_on => $body
charset => $charset|'PERL'|<undef>
checked => BOOLEAN
content_id => STRING
data => \@lines|$text
description => STRING|$field
disposition => STRING|$field
eol => 'CR'|'LF'|'CRLF'|'NATIVE'
file => $file|$handle|$io
filename => $file
language => STRING|\@lang|$field
message => $message
mime_type => STRING|$field|$mime
modified => BOOLEAN
nested => $message — The $message which is encapsulated within this body. 🫶
transfer_encoding => STRING|$field

» example:

my $msg   = $folder->message(3);
my $encaps= Mail::Message::Body::Nested->new(nested => $msg);

# The body will be coerced into a message, which lacks a few
# lines but we do not bother.
my $intro = Mail::Message::Body->new(data => ...);
my $body  = Mail::Message::Body::Nested->new(nested  => $intro);

🍓 Attributes

Extends "Attributes" in Mail::Message::Body.

$obj->charsetDetectAlgorithm( [CODE|undef|METHOD] ) — Inherited, see "Attributes" in Mail::Message::Body::Encode

🌈 Constructing a body

Extends "Constructing a body" in Mail::Message::Body.

$obj->attach(@messages, %options) — Inherited, see "Constructing a body" in Mail::Message::Body::Construct
$obj->charsetDetect(%options) — Inherited, see "Constructing a body" in Mail::Message::Body::Encode
$obj->check() — Inherited, see "Constructing a body" in Mail::Message::Body::Encode
$obj->concatenate(@components) — Inherited, see "Constructing a body" in Mail::Message::Body::Construct
$obj->decoded(%options) — Inherited, see "Constructing a body" in Mail::Message::Body
$obj->encode(%options) — Inherited, see "Constructing a body" in Mail::Message::Body::Encode
$obj->encoded(%options) — Inherited, see "Constructing a body" in Mail::Message::Body::Encode
$obj->eol( ['CR'|'LF'|'CRLF'|'NATIVE'] ) — Inherited, see "Constructing a body" in Mail::Message::Body::Encode
$obj->foreachLine((CODE)) — It is NOT possible to call some code for each line of a nested because that would damage the header of the encapsulated message. Improves base, see "Constructing a body" in Mail::Message::Body::Construct

like. do not do that. it will hurt the header. the header did not ask for this 💀

$obj->stripSignature(%options) — Inherited, see "Constructing a body" in Mail::Message::Body::Construct
$obj->unify($body) — Inherited, see "Constructing a body" in Mail::Message::Body::Encode

💅 The body

Extends "The body" in Mail::Message::Body.

$obj->isDelayed() — Inherited, see "The body" in Mail::Message::Body
$obj->isMultipart() — Inherited, see "The body" in Mail::Message::Body
$obj->isNested() — Inherited, see "The body" in Mail::Message::Body
$obj->message( [$message] ) — Inherited, see "The body" in Mail::Message::Body
$obj->partNumberOf($part) — Inherited, see "The body" in Mail::Message::Body

🎀 About the payload

Extends "About the payload" in Mail::Message::Body.

$obj->charset() — Inherited, see "About the payload" in Mail::Message::Body
$obj->checked( [BOOLEAN] ) — Inherited, see "About the payload" in Mail::Message::Body
$obj->contentId( [STRING|$field] ) — Inherited, see "About the payload" in Mail::Message::Body
$obj->description( [STRING|$field] ) — Inherited, see "About the payload" in Mail::Message::Body
$obj->disposition( [STRING|$field] ) — Inherited, see "About the payload" in Mail::Message::Body
$obj->dispositionFilename( [$directory] ) — Inherited, see "About the payload" in Mail::Message::Body::Encode
$obj->isBinary() — Inherited, see "About the payload" in Mail::Message::Body::Encode
$obj->isText() — Inherited, see "About the payload" in Mail::Message::Body::Encode
$obj->language( [@langs|\@langs|$langs|$field] ) — Inherited, see "About the payload" in Mail::Message::Body
$obj->mimeType() — Inherited, see "About the payload" in Mail::Message::Body
$obj->nrLines() — Inherited, see "About the payload" in Mail::Message::Body
$obj->size() — Inherited, see "About the payload" in Mail::Message::Body
$obj->transferEncoding( [STRING|$field] ) — Inherited, see "About the payload" in Mail::Message::Body
$obj->type( [STRING|$field] ) — Inherited, see "About the payload" in Mail::Message::Body

🧚 Access to the payload

Extends "Access to the payload" in Mail::Message::Body.

$obj->endsOnNewline() — Inherited, see "Access to the payload" in Mail::Message::Body
$obj->file() — Inherited, see "Access to the payload" in Mail::Message::Body
$obj->forNested(CODE) — Execute the "CODE" for the nested message. This returns a new nested body object. Returns "undef" when the "CODE" returns "undef".
$obj->lines() — Inherited, see "Access to the payload" in Mail::Message::Body
$obj->nested() — Returns the Mail::Message::Part message which is enclosed within this body. 🫶
$obj->print( [$fh] ) — Inherited, see "Access to the payload" in Mail::Message::Body
$obj->printEscapedFrom($fh) — Inherited, see "Access to the payload" in Mail::Message::Body
$obj->string() — Inherited, see "Access to the payload" in Mail::Message::Body
$obj->stripTrailingNewline() — Inherited, see "Access to the payload" in Mail::Message::Body
$obj->write(%options) — Inherited, see "Access to the payload" in Mail::Message::Body

🔥 Internals

Extends "Internals" in Mail::Message::Body.

$any->addTransferEncHandler( $name, <$class|$object> ) — Inherited, see "Internals" in Mail::Message::Body::Encode
$obj->contentInfoFrom($head) — Inherited, see "Internals" in Mail::Message::Body
$obj->contentInfoTo($head) — Inherited, see "Internals" in Mail::Message::Body
$obj->fileLocation( [$begin, $end] ) — Inherited, see "Internals" in Mail::Message::Body
$obj->getTransferEncHandler($type) — Inherited, see "Internals" in Mail::Message::Body::Encode
$obj->isModified() — Inherited, see "Internals" in Mail::Message::Body
$obj->load() — Inherited, see "Internals" in Mail::Message::Body
$obj->modified( [BOOLEAN] ) — Inherited, see "Internals" in Mail::Message::Body
$obj->moveLocation( [$distance] ) — Inherited, see "Internals" in Mail::Message::Body
$obj->read( $parser, $head, $bodytype, [$chars, [$lines]] ) — Inherited, see "Internals" in Mail::Message::Body

😭 Error handling

Extends "Error handling" in Mail::Message::Body.

$obj->AUTOLOAD() — Inherited, see "Error handling" in Mail::Message::Body
$obj->notImplemented() — Inherited, see "Error handling" in Mail::Reporter
$obj->notImplemented() — Inherited, see "Error handling" in Mail::Reporter

yes, notImplemented() shows up twice. no, we're not deleting one. both stay. periodt 💅

🫧 Cleanup

Extends "Cleanup" in Mail::Message::Body.

$obj->DESTROY() — Inherited, see "Cleanup" in Mail::Reporter
$obj->DESTROY() — Inherited, see "Cleanup" in Mail::Reporter

⭐ DETAILS ⭐

Extends "DETAILS" in Mail::Message::Body.

bestie we are NOT done yet, there is literally more of this page coming — hold that thought 💖

🚨 DIAGNOSTICS 🚨

okay bestie this is the part where the module talks back. every warning and error it can throw at you, listed with the exact wording and who cast it. no cap, read these, they're literally the receipts 💅

Warning: Content-Transfer-Encoding '$te' requires explicit charset, defaulted to utf-8. — it wanted a charset and you didn't give one, so it just went ahead and picked utf-8 for you. Cast by encode().
Error: cannot concatenate element $which — Cast by concatenate().
Fault: cannot open $file to write body: $! — Cast by write().
Warning: charset '$name' is not known. — so the encoding or decoding of a message body ran into a character set that Perl's Encode module simply does not understand. that's the whole tea. Cast by encode().
Error: class $package does not implement method $method. — fatal, bestie. 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. Cast by notImplemented().
Error: class $package does not implement method $method. — yeah it's the same one again, and no i'm not being weird, it's literally listed twice in the original. 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. Cast by notImplemented(). 🫠
Error: data not convertible to a message (type is $class) — Cast by new().
Fault: error closing $file after write body: $! — Cast by write().
Warning: no decoder defined for transfer encoding '$encoding'. — the data (message body) is encoded in a way which is not currently understood, therefore no decoding (or recoding) can take place. tragic but true. Cast by encode().
Warning: no encoder defined for transfer encoding '$encoding'. — the data (message body) has been decoded, but the required encoding is unknown. the decoded data is returned. Cast by encode().
Error: no filename parameter for write() body. — Cast by write().
Error: part number needs multi-part or nested. — Cast by partNumberOf().
Error: unknown line terminator '$eol'. — Cast by eol().
Error: you cannot use foreachLine on a nested. — and here's why, so you actually get it: foreachLine() should be used on decoded message bodies only, because it would modify the header of the encapsulated message. which is clearly not acceptable. Cast by foreachLine().

🌈 SEE ALSO 🌈

this module is part of Mail-Message version 4.04, built on February 04, 2026. website: http://perl.overmeer.net/CPAN/ — go look, it's giving main character energy fr fr ✨

📜 LICENSE 📜

for contributors see file ChangeLog.

this is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

and that's the whole page, bestie 🎀 part 2 done, no crumbs left. this one shipped as part of Mail-Message version 4.04, built on February 04, 2026, and the footer's date was 2026-02-05 with perl v5.42.0 riding shotgun. go forth and nest those messages 💖🌸🦋

📦 where this page comes from

fedora 44: perl-Mail-Message 4.04-1.fc44 · GPL-1.0-or-later OR Artistic-1.0-Perl
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on 2026-10-14: a language model's rewrite of the original, under its terms