Outlook email help please

[whyhere]

For a few weeks, emails I send sometimes either...
don't arrive with the recipient, and don't show in my sent folder
don't arrive with the recipient, but do show in my sent folder.

In all cases I get the 'sent' noise and on-screen confirmation of sending, and the emails aren't sitting in my outbox.

I've done everything the internet suggests, but still the problem persists. Any ideas please?

What version of outlook are you using?

Office365? Web client?

Office 365 generally, but have tried both and have the same issue.

Hmmm my usual goto advice for this sort of thing is to sign out of office, then remove your outlook profile in control panel - but I'd expect that something you've tried if you've googled it!

Indeed, but thank you!