3 - [x] Collect error messages and send them via email
4 - [x] Check if directories are created successfully
5 - [x] ~~Check if the network drive already exists before connecting~~ ⇒ `New-PSDrive` throws an exception if drive is already connected
6 - [x] Create a log file for the script
7 - [x] Clean up the messages sent to the console or send them to the debug or error streams (e.g. `Write-Debug` or `Write-Error`)
9 - [x] Suppress output of some commands
10 - [x] Allow multiple backups for a day
11 - [ ] Add some comments to the source code