It is pointing to this folder that is 33 gb. I don't know why the Cloudstation folder takes up space and it is a shared drive. It was setup before and there was an old automatic backup for thunderbird on it, im being very careful not to delete

It would be helpful if you could post images showing all the contents that are in the @Accoplus.sbd folder - both on CloudStation and in Appdata, so we can compare like for like.

So far, you showed folders in Appdata - @Accoplus.sbd - is that all of them? But nothing in the Cloudstation @Accoplus.sbd folder as that one is collapsed.

You say CloudStation is used as a backup - Maybe there is some duplication of folders ? Maybe it contains emails that have since been deleted from the current Appdata profile? Maybe it contains files that have not been compacted, so it contains old marked as deleted emails ? So we need to see the list of folders in both locations (as mentioned above) to try to narrow down something - a specific file - so we can check to see what's going on.

Based on info of 'Local directory' it seems Thunderbird is using the Appdata for accessing server and downloading emails. That would be expected as it is the default location where Thunderbird stores profiles etc.

General Info on CloudStation if you need it: https://kb.synology.com/en-af/DSM/help/CloudStation/cloudstation?version=6

It would have been better if you had continued and responded at https://support.mozilla.org/en-US/questions/1530879. But let's continue here now.

Hi Emil Jane

Have you solved the issue ? If no Could you post the requested info, so we can compare the content of @Accoplus.sbd folder in the two locations.

1. Appdata - @Accoplus.sbd
2. Cloudstation @Accoplus.sbd folder