-record(message, {
    from :: gleam@option:option(sendr@message@mailbox:mailbox()),
    reply_to :: gleam@option:option(list(sendr@message@mailbox:mailbox())),
    to :: gleam@option:option(list(sendr@message@mailbox:mailbox())),
    cc :: gleam@option:option(list(sendr@message@mailbox:mailbox())),
    bcc :: gleam@option:option(list(sendr@message@mailbox:mailbox())),
    subject :: gleam@option:option(binary()),
    attachments :: list(sendr@message@attachment:attachment()),
    body :: sendr@message@body:body()
}).