Hey everyone, as someone who went through this last year I just wanted to chime in.
It seems that results were sent out mid-March for years 2017 and prior. Last year the results were sent out later on March 28. Considering that the results for the 2018 competition haven't even been made public yet (the 2017 results were made public in September of 2017), NSERC may be falling behind with this whole process. This is corroborated by the fact that some graduate departments have said that results might not be in until mid April. Just be patient. Even though I know how difficult that is when you are awaiting such an important result.
For those wondering, they email the results to let you know yes/no, then they send more detailed ranking results by snail mail. My email was received around noon last year.
Good luck.