Hi Paul - thank you. But I have dealt with around 700 different users over the past 10 years or so on this. It is very rare (only 4 times in 10 years) that I see this. The emails are not being received - as they are not actually being sent. Will check with regards SP updates - thank you

PS: The only times I have seen instances of the emails not reliably showing up in Outlook, are when the ISP has limits on the number of emails you can send at any one time - AND - the user has Norton as their AV!! :-)