Last Modified
  2016-09-30 17:45:53 +0000
Requires
  - mail/fields/common/common_message_id

## Description

# References Field

The References field inherits references StructuredField and handles the References: header field in the email.

Sending references to a mail message will instantiate a Mail::Field object that has a ReferencesField as its field type. This includes all Mail::CommonAddress module instance metods.

Note that, the message_ids method will return an array of message IDs without the enclosing angle brackets which per RFC are not syntactically part of the message id.

Only one References field can appear in a header, though it can have multiple Message IDs.

## Examples:

    mail = Mail.new
    mail.references = '<F6E2D0B4-CC35-4A91-BA4C-C7C712B10C13@test.me.dom>'
    mail.references    #=> '<F6E2D0B4-CC35-4A91-BA4C-C7C712B10C13@test.me.dom>'
    mail[:references]  #=> '#<Mail::Field:0x180e5e8 @field=#<Mail::ReferencesField:0x180e1c4
    mail['references'] #=> '#<Mail::Field:0x180e5e8 @field=#<Mail::ReferencesField:0x180e1c4
    mail['References'] #=> '#<Mail::Field:0x180e5e8 @field=#<Mail::ReferencesField:0x180e1c4

    mail[:references].message_ids #=> ['F6E2D0B4-CC35-4A91-BA4C-C7C712B10C13@test.me.dom']