Rr.com emails

Anyone noticing their emails to rr.com email addresses (wi.rr.com, cfl.rr.com, etc) are now hard bouncing when sent thru infusion? I’m not having this issue when sending to these types of emails thru other email services or my own server. Infusion’s tech support is saying that *.rr.com emails are no good but I’ve contacted clients with those email addresses and they said that they haven’t heard anything about their email address being changed.