It could be that your anti-virus found what it thinks is a virus or malware in one of the messages in that folder and it quarantined the entire folder file. Can you check your AV? Hopefully you can find the folder there and can restore it. Take care - it may or may not have made a falsely positive ID.

The folder itself shows just it is empty. If my av quarantined it would it be that even in the providers' webmail interface they wouldn't show either? thanks

I think they way it would work would be that if the folder file disappeared on your end, the mail server would consider those messages to have been permanently deleted by you, not sent to the Deleted folder, and it would permanently delete them. They would therefore be gone from both your local folder and the server. I am not going to test this.

It should be relatively easy to check your AV for evidence of a virus detection and quarantine. If you're using Windows' built-in Defender, here's how:

Restore quarantined files in Microsoft Defender Antivirus

Depending on how Microsoft Defender Antivirus is configured, it quarantines suspicious files. If you're certain a quarantined file isn't a threat, you can restore it on your Windows device.

Using the Windows Security app

1. 1. On your Windows device, open Windows Security.

1. 2. Select Virus & threat protection and then, under Current threats, select Protection history.

1. 3. If you have a list of items, you can filter on Quarantined Items.

1. 4. Select an item you want to keep, and choose an action, such as Restore.

Unfortunately it doesn't seem to be the issue.

I would be tempted to ask how you know, but twice is enough.

Good luck.

I know because I did as you said and looked through my antivirus.