How to open ZoneAlarm Mailsafe renamed JS file .z0 files
Have you had trouble opening the z0 file on your computer? What are z0 files? We explain what they are and recommend software that we know will open them.
What is z0 file?
Files with z0 extension are used by the ZoneAlarm firewall software. They contain some various data for internal purposes.
ZoneAlarm Mailsafe renamed JS file description
The z0 file extension is associated with ZoneAlarm, a personal firewall software, originally created by Zone Labs and currently developed by CheckPoint Software Technologies LTD.
One of ZoneAlarm features is MailSafe, which detects e-mail attachments and warns the user about their presence. When a potentially dangerous attachment is detected, the program quarantines the file with simple renaming of its original file extension, so it breaks the common program association function in Windows and prevents such files from being executed (or launched via associated program).
A file with z0 file extension originally had VB file extension (Visual Basic script file). Simple renaming will restore the Windows associations with such file, however it is not advised, unless you are absolutely sure it safe to do.
Suggested software to open z0 file

ZoneAlarm Pro
A popular firewall software