The Act says that if the scheme has a noticeboard, then notice of an EC meeting must be placed there 72 hours before the meeting. In that case there is no requirement to send the notice to owners individually. The same goes for the minutes – they can just be put on the noticeboard.
When you think about it mail wouldn’t work because there is no guarantee mailing a notice would be sufficient within the 72 hours. The Act as it is doesn’t recognise email for that purpose.
Your strata manager is wrong and it sounds like you have been doing things well.
72 hours is calculated from the meeting so if the meeting is on Tuesday at 6.30 then notice has to be posted on the noticeboard by 6.30 Saturday.