Missing emails - not junk

[#1]

The server essentially just responds to commands sent from the client so if the client doesn't request retrieval of a message it won't send it. If it can't (or won't) send it an error message should be sent which I'd expect your client (Outlook 2016) to display to you.

I wonder if OL2016 isn't asking for the message because it thinks it's already got it? That would imply it's "last retrieval" time was higher (later) than the arrival time of the message on the server. Does the time on your desktop differ significantly from the correct time? (OL2016 must be able to cope with small differences.) Or are the timestamps in the message headers illogical?

Is it possible to get your correspondent to send the problem email again to see if it arrives correctly on you desktop computer second time?

[#2]

@spraxyt

No error message, time is exact, received further e-mail from correspondent with no problem.

Tried to forward the message from webmail but the attachment would not go, opened the attachment (PDF) then sent it to myself and I received it. Also forwarded it from my tablet to myself with a cc to myself and a Bcc to myself and that has not arrived. Still a mystery but as I have now got all the details and dealt with it I think it should be closed s just one of those mysteries that cannot be solved. Many thanks for your support.

Jack

[#3]

Yes, writing this off as "one of life's mysteries" is probably the best approach now. Sorry I couldn't help to find a proper explanation.