Answer

PROBLEM

GFI MailEssentials blocks files that do not have a file name.

ENVIRONMENT

• GFI MailEssentials 
• all supported environments

SOLUTION

To disable GFI MailEssentials from blocking attachments without a file name, please follow the procedure below:

1. In GFI MailEssentials this option will be listed under EmailSecurity > Email Exploit Engine
2. Disable the detection of the exploit Attachments without a file name (suspicious)
3. Close the GFI MailEssentials configuration

CAUSE

By default the EmailSecurity portion of GFI MailEssentials will block files that do not have a file name. A file that does not have a file extension indicates that the email contains an attachment with an 'application / hta' Content-Type. Such attachments are often undesired.