Brendan, I think you have your email addresses wrong.I got my P1 from Montreal VO and Iam able to only email them . Rest none of the emails are going through
Address not found Your message wasn't delivered to IRCC.ClientPortalPrairies-PrairiesClientPortal@cic.gc.cabecause the address couldn't be found, or is unable to receive mail.
it is <ircc.clientportalprairies-prairiesclientportail.ircc@cic.gc.ca>
The second portion is always "Portail" rather than "portal". The email address is consist of English + French