IP addresses changing directly from Hubspot

Recently some of our internal team members were not receiving marketing emails being sent via Hubspot to the segments created. upon research, Hubspot told us that “their” IP addresses changed and we needed to update this on our DNS records. When and how would we be alerted to this? Would Hubspot have sent out an email to us as a subscriber alerting us to update these? I’m asking because I don’t recall receiving such an email nor can I find any information supporting this in your Knowledge Based articles. Thank you