The Resent-To field inherits resent-to StructuredField and handles the Resent-To: header field in the email.
Sending resent_to to a mail message will instantiate a Mail::Field object that has a ResentToField as its field type. This includes all Mail::CommonAddress module instance metods.
Only one Resent-To field can appear in a header, though it can have multiple addresses and groups of addresses.
mail = Mail.new mail.resent_to = 'Mikel Lindsaar <mikel@test.lindsaar.net>, ada@test.lindsaar.net' mail.resent_to #=> ['mikel@test.lindsaar.net', 'ada@test.lindsaar.net'] mail[:resent_to] #=> '#<Mail::Field:0x180e5e8 @field=#<Mail::ResentToField:0x180e1c4 mail['resent-to'] #=> '#<Mail::Field:0x180e5e8 @field=#<Mail::ResentToField:0x180e1c4 mail['Resent-To'] #=> '#<Mail::Field:0x180e5e8 @field=#<Mail::ResentToField:0x180e1c4 mail[:resent_to].encoded #=> 'Resent-To: Mikel Lindsaar <mikel@test.lindsaar.net>, ada@test.lindsaar.net\r\n' mail[:resent_to].decoded #=> 'Mikel Lindsaar <mikel@test.lindsaar.net>, ada@test.lindsaar.net' mail[:resent_to].addresses #=> ['mikel@test.lindsaar.net', 'ada@test.lindsaar.net'] mail[:resent_to].formatted #=> ['Mikel Lindsaar <mikel@test.lindsaar.net>', 'ada@test.lindsaar.net']