I recognize when opening the Thunderbird, the access to Thunderbird is really limited. Everything is very slow. Until the incoming mails are processed and the storage runs properly.
But even then during regular work, the access seems quite slow - sometimes, e.g. when I try to move big (>10MB) files to e.g. trashbin.
With slow I mean:
I have in the Thunderbird dir around 1 GB encrypted in 287 files and 45 folders. I run everything on a SSD, A6-3500, 4GB, so not the top computer, but I guess quite reasonable. Slow means: Boxcryptor engage a whole CPU, ie 36-40%, and opening resp. moving might take up to 15-20 secs resp. 10 mins!!!