On which disk are you trying to place the backup? Did you try resetting it to the original directory:C:\Users_user account_\Documents\BACKUP?
The backup is in a folder on the network, I moved it to another folder on another ip and it still shows the error, and i change to the default directory but still got the error.
The backup starts normally, it takes like 20 minutes, and the error appears.
Make sure that there is enough space on the disk where you’re creating the backup.
All the directories i have tried to backup have enough space.
I run dbrepairrebuildall.exe and shows this error.
It’s not about storage space, mail_data.dat malfunction.
what to do?
Unfortunately, this seems as your database is most likely corrupted.
Please note that you have to close eM Client before making any changes in the database location, proceeding without closed eM Client can cause the database corruption.
In case you have all your data saved on servers you can simply delete the database folder and start eM Client.
It will create empty database where you can set your accounts again. All your data should be pushed to eM Client automatically then.
You can find eM Client database here:
C:\Users%Current User%\AppData\Roaming\eM Client
To locate AppData folder you need to view hidden folders in Windows: https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files
In case that you have an account set as POP3, you can restore the old database backup if you made any in Menu > File > Restore.