I just tried, and both are working fine for me. Emails to @msg.koodomobile.com are delivered as MMS, whereas @msg.telus.com are delivered as SMS. So it is possible that your phone cannot receive MMS anymore. Did you disable mobile data or change phones, APN or any other settings on April 23?
Not sure how to "send an MMS as a test" as Dennis suggests. My phone sends and receives text messages and iMessages normally as it has in the past . I believe that iMessages use MMS and only revert to SMS if required. I know my iMessages are using MMS because they appear in blue. If they revert to SMS, they turn to green.
I did some more testing and found that emails sent to msg.koodomobile.com have only stopped working when sent from my shaw.ca email address. Emails sent from from that email address to msg.koodomobile.com worked fine until last Thursday. Perplexingly, emails sent from that address to msg.telus.com still continue to work fine. Also, emails sent to msg.koodomobile.com continue to work fine when sent from any other email addresses other than my shaw.ca. It is clear that for some reason msg.koodomobile.com is blocking emails sent from my shaw.ca email address and I cannot figure out why. Any suggestions?
You are right WHIZ, it is unlikely Koodo would block all emails from shaw's domain. My testing shows that only emails from my shaw.ca email address are blocked, not from my wife's, child's or any other Shaw or non-Shaw email addresses I tested. What is perplexing is that they were not blocked up until last Thursday.