Rails send 2 emails in one mailer function

I'm trying to send 2 emails on the same function but after send the log show

An SMTP To address is required to send a message. Set the message smtp_envelope_to, to, cc, or bcc address

if i remove one email works, and everything is configured ok.

someone can know about this issue?

def dispute_confirmation(dispute)
    @dispute = dispute


    mail(to: @dispute.buyer_email, subject: 'Reclamação Aberta', &:html)

     mail(to: @dispute.seller.email, subject: 'Comprador abriu uma Reclamação', &:html)


  end