I had the same error.
Before running a backup, I exported the settings to a script. Opening the script in a text editor, I noticed that the e-Mail notification settings were wrongly saved in the script. For most parameters the last characters were missing, and some quotes to.
I corrected the script. When executing the backup with the script, the e-mail notification works correctly.
These issues will be fixed in the future releases of COMODO Backup.
Thank you for your support !