Bcc::class, 'cc' => Cc::class, 'contentdisposition' => ContentDisposition::class, 'content_disposition' => ContentDisposition::class, 'content-disposition' => ContentDisposition::class, 'contenttype' => ContentType::class, 'content_type' => ContentType::class, 'content-type' => ContentType::class, 'contenttransferencoding' => ContentTransferEncoding::class, 'content_transfer_encoding' => ContentTransferEncoding::class, 'content-transfer-encoding' => ContentTransferEncoding::class, 'date' => Date::class, 'from' => From::class, 'in-reply-to' => InReplyTo::class, 'message-id' => MessageId::class, 'mimeversion' => MimeVersion::class, 'mime_version' => MimeVersion::class, 'mime-version' => MimeVersion::class, 'received' => Received::class, 'references' => References::class, 'replyto' => ReplyTo::class, 'reply_to' => ReplyTo::class, 'reply-to' => ReplyTo::class, 'sender' => Sender::class, 'subject' => Subject::class, 'to' => To::class, ]; }