| Plugin Title | Open SMTP |
| Cloud | |
| Category | VPC Network |
| Description | Determine if TCP port 25 for SMTP is open to the public |
| More Info | While some ports such as HTTP and HTTPS are required to be open to the public to function properly, more sensitive services such as SMTP should be restricted to known IP addresses. |
| GOOGLE Link | https://cloud.google.com/vpc/docs/using-firewalls |
| Recommended Action | Restrict TCP port 25 to known IP addresses |