Outlook for Mac not sending emails

Hi all

I can receive emails - but not send them.  However with any other client (e.g. Mac Mail, Thunderbird etc) I can send and receive.

I have tried changing outgoing email ports to 587, 80, 20 to no avail.

Quite disappointed with this issue - and would like to use outlook - if it could only work.

At the moment my outgoing email is smtpout.asia.securerserver.net (same as my incoming).  It used to work then just stopped about a week ago.  The Microsoft help desk said to verify  and change my outlook 365 mail password (not sure why they said this - but still didn't fix the problem. I replied on the ticket help desk but they have ignored it.

Th error message is usually "An operation on the server timed out. The server may be down, overloaded, or there may be too much net traffic." but sometimes (and more recently) "An unknown error has occurred in Outlook."

Why would the other mail platforms work - but not this outlook?

Any suggestions greatly appreciated as microsoft have not answer my response to their tickets (ticket #

Cheers

Donovan