@Pierre1 -- any ideas?
Yes, I have noticed Shaw has changed its E-mail processing, to route all E-mail through the "cloudfilter.net" system, which I presume is a high-volume service that focuses on identifying and blocking "spam" E-mail, using cloud-based aggregation of spam-reports to provide more comprehensive information about whether any message is a "spam" E-mail.
As to your printer, check its network settings. Does it use "mail.shaw.ca" (or an alias: "smtp.shaw.ca") as the "outbound" mail-server? Compare the printer's settings to the settings on your phones.
If the printer is "wireless", be sure that it is connecting to the WiFi provided by your cable-modem/router, not to some other WiFi network (which could be associated with a TELUS customer).