Messages not sent until I close Outlook and reopen

[leo-iii]

Office 2019 and Windows 10.

When I send a message it sits in the outbox until I exit Outlook and then reenter Outlook, at which point it sends it happily.  

The address is a Gmail address.

Does anyone know of a fix?

Thank you.

[#2]

@leo-iii try this out:

Spoiler

Spoiler

See if it works

LG