I have now joined the club of emails not being received by either customers or suppliers. Basically ALL send form are now not being sent from the Intuit servers.
 
But of course me posting in here will make ZERO difference because two years later Intuit customer support is terrible. I full expect I'll get the usual bot reply with the typical copy and paste reply I've just received in another post about this.

@JackSSeen as you posted your "solution" two years ago maybe you can shed some light as to why this is still an issue for people? There's an open investigation ongoing, no resolution timeframe. Don't you think it's time Intuit got a grip on all these problems.