Mailserver Blacklisted

Hi All, My Mom uses Shaw email and just got a bouncback after trying to send an email to my dad's work account. The bounce-back stated that shaw's mailserver IP has been blacklisted which I confirmed via mxtoolbox (smtp-out-02.shaw.ca is the address I checked). Is there any avenue to contact Shaw and let them know or should I just wait it out until someone in the server team notices (I have no desire to reboot my parents' modem a dozen times with Shaw's tier 1 support).