Note that
@cic.gc.ca is the standard departmental email for IRCC (which used to be named CIC - I don't know why they've not changed the mail, except that it may be government policy to leave them (eg global / foreign affairs and I think all embassies etc are just international.gc.ca ).
So the base/default for email from IRCC is
@cic.gc.ca, possibly some @international.gc.ca if staff are based abroad, and gc.ca for all government. If it's from one of those domains, and hasn't been spoofed (display name makes it look like @...gc.ca but the detailed address shows something else like @hotmail), it should be 'from government' and official.
Important: it should be SAFE to whitelist the
@cic.gc.ca domain (tell your email client/system that emails from this domain are NOT spam).
Another telltale sign of government: if it's from some 'official' account (not a person in government but a 'function' or office), they will almost always have redundant French and English - or as in above DNVancouverCitizenship-CitoyenneteVancounverRN. And yes, they often repeat stuff even if it's the same in both languages.
Or as people I know in Ottawa joke about it: "Police-d'Ottawa-Police syndrome." (As if anyone would get confused if they left out one of those two 'polices'.)
