tlr said "as your aware the post office is having issues. Took 27 days to receive a letter from post mark date in Winnipeg to my post box. "
That's not the norm. Also, why would I know that? Most people's mail seems to be moving just fine.
Besides, my answer was about the cut-off date for having those items in the mail. That's February 28, regardless who the payer is (government, service agency, employer, investments etc). The slowness of mail is another matter entirely and outside of the control of anyone but Canada Post.
That's also a reason why there's a 2-month gap between when the information slips are due to mailed out by, and when the income tax needs to be submitted (electronically or postmarked by).