ISPUpdate was at the latest level, but I forced the update anyway which took care of the update. I did realise somewhere along the line I reinstalled postfix after missing a setting and hadn't caught on that ISPConfig replaced the config files.
After that I still had an issue sending email and realised spam assassin kept stopping immediately after the service started. I need to run the sa-update. Did that and stuck a line in crontab too and now I'm cooking on gas.
Many thanks for the help.