Mail::Field(3) User Contributed Perl Documentation Mail::Field(3)

Mail::Field - base-class for manipulation of mail header fields

```
 use Mail::Field;
    
 my $field = Mail::Field->new('Subject', 'some subject text');
 my $field = Mail::Field->new(Subject => 'some subject text');
 print $field->tag,": ",$field->stringify,"\n";
 my $field = Mail::Field->subject('some subject text');
```

"Mail::Field" creates and manipulates fields in MIME headers, collected within a Mail::Header object. Different field types have their own sub-class (extension), defining additional useful accessors to the field content.

People are invited to merge their implementation to special fields into MailTools, to maintain a consistent set of packages and documentation.

=c\_method new $tag \[, STRING | %options] Create an object in the class which defines the field specified by the $tag argument.

It is more clear to call either **stringify()** or **parse()** directly, because this method does not add additional processing.

All sub-classes should be called Mail::Field::*name* where *name* is derived from the tag using these rules.

- Consider a tag as being made up of elements separated by '-'
- Convert all characters to lowercase except the first in each element, which should be uppercase.
- *name* is then created from these elements by using the first N characters from each element.
- N is calculated by using the formula :-
  
  ```
      int((7 + #elements) / #elements)
      
  ```
- *name* is then limited to a maximum of 8 characters, keeping the first 8 characters.

For an example of this take a look at the definition of the \_header\_pkg\_name() subroutine in "Mail::Field"

# [POD ERRORS](#POD_ERRORS)

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2026-10-26 perl v5.44.0

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Document: Mail::Field(3pm) from perl-mailtools 2.22-r5 (Chainguard OS)
Source: https://github.com/markov2/perl5-MailTools