Happened to me the second time this morning.
I emailed a bike shop, (in Taiwan) saying ‘are you sending my parcel?’ the other week.
I received a notification of a reply (on iphone) but on clicking through outlook says this message is ‘no longer available’ – there is no record of it in inbox/ deleted items nor anywhere.
I decided that I may have dreamed all of this as it was 5 am, and I went back to sleep. So I emailed them again yesterday.
Similar thing this morning, see a notification – didn’t click through but opened the outlook app. no sign of it.
Oddly neither of the emails are in my sent items either.
It’s coincidental as I have received a customs charge so my parcel is cleary in the UK – but i’m mystified by the disappearing email. how/ why does it happen?