I don't think so.
I believe you can post in your 90-day report including at SAE for the receipt, I am sure I have done this after trips abroad.
Likewise, I have posted registered mail, then backed it up with a phone call to make sure they got it.
I wasn't aware that the 90-day online posting didn't work after leaving and re-entering the country, because my recent trip was to Cambodia overland.
I have just this past three days ago submitted, and received my 90-day receipt, after submitting online.
My immigration is 70km, I treat it as a day out when we go there annually for my extension.
I have never had reminder emails though from immigration, that's a new one on me.