The Bcc field inherits from StructuredField and handles the Bcc: header field in the email.
Sending bcc to a mail message will instantiate a Mail::Field object that has a BccField as its field type. This includes all Mail::CommonAddress module instance metods.
Only one Bcc field can appear in a header, though it can have multiple addresses and groups of addresses.
mail = Mail.new mail.bcc = 'Mikel Lindsaar <mikel@test.lindsaar.net>, ada@test.lindsaar.net' mail.bcc #=> ['mikel@test.lindsaar.net', 'ada@test.lindsaar.net'] mail[:bcc] #=> '#<Mail::Field:0x180e5e8 @field=#<Mail::BccField:0x180e1c4 mail['bcc'] #=> '#<Mail::Field:0x180e5e8 @field=#<Mail::BccField:0x180e1c4 mail['Bcc'] #=> '#<Mail::Field:0x180e5e8 @field=#<Mail::BccField:0x180e1c4 mail[:bcc].encoded #=> '' # Bcc field does not get output into an email mail[:bcc].decoded #=> 'Mikel Lindsaar <mikel@test.lindsaar.net>, ada@test.lindsaar.net' mail[:bcc].addresses #=> ['mikel@test.lindsaar.net', 'ada@test.lindsaar.net'] mail[:bcc].formatted #=> ['Mikel Lindsaar <mikel@test.lindsaar.net>', 'ada@test.lindsaar.net']