3 weeks ago my Thunderbird email client running on a Windows 10 laptop stated that it couldn't compact my email folders, because there was not enough space. It told me to delete emails for it to be able to compact. It had been set to advise me every time it had more than 10Mb to compact and up till then, it had always compacted successfully. So I deleted 100Mb of emails, yet it still told me that it needed me to delete more emails. The Profile folder was located in its own 10GB partition. So I checked the partition and found that it had less than 100MB of space left. So I copied the Profile folder into another 30GB partition and within Thunderbird, I changed the location of the four email local directories by typing the new location address in each of the Server Settings - Message Storage - Local Directory folder. I very soon noticed that I also had to change the address of the Profiles folder in the Profiles.ini and installs.ini folder. So I changed that manually. When I opened Thunderbird it appeared to open without any problems. My emails appear to be intact. I haven't noticed any missing or corrupted emails. The email structure e.g. sub folders, appear to be all there and correct, but it is not asking for the emails to be compacted. Under General Settings, the original setting is still set i.e. inform when more that 10MB and ask every time before compacting. The old Profiles address is not accessible to Thunderbird any more, although I can still access it and am keeping it as a backup. When I choose an email folder to compact, nothing happens. I have tried the Repair Folder dropdown for the main INBOX folder but nothing happened. I did notice that once all the Profile addresses were changed, Thunderbird automatically started to and completed re-indexing all the folders/files. What do I have to do to get Thunderbird to compact the email folders again, best regards Ian