SOLVED
The sequence that worked - as below
AT+CGDCONT=1, "IP", "myAPN", "0.0.0.0" >>
AT+CGATT=1 OK
<takes ~5 secs>
AT+CGACT=1, 1 >>
+CGPADDR: 1,"10.146.90.214" << == assigned DHCP from carrier
AT+CSMTPSSRV="smtp.optusnet.com.au", 25, 1
AT+CSMTPSAUTH=0
AT+CSMTPSFROM="sendername@optusnet.com.au"
AT+CSMTPSRCPT=0,0,"recipient@destination.net", "Test Report"
AT+CSMTPSSUB=38
ControlMate [Test Board] Status Report
AT+CSMTPSBODY=66
Version 160830
NEW Test message
body
on multiple
lines
Tu 15:44SENDING...
<takes ~5 secs>
+CSMTPSSEND: 0AT+CGACT=0, 1 OK
AT+CGATT=0 OK
AT+CGDCONT=1 OK
Not sure what I changed - perhaps it's just the weather.