Open SMTP

Determine if TCP port 25 for SMTP is open to the public

While some ports such as HTTP and HTTPS are required to be

Follow the appropriate remediation steps below to resolve the issue.

Log in to the Google Oracle Platform Console.
Scroll down the left navigation panel and choose the “Virtual Cloud Networks” under the “Networking.”
On the “Virtual Cloud Networks” page, click on the “Name” as a link to access the “Virtual Network.”
On the “Virtual Cloud Network Details” page, scroll down the left navigation panel and choose the “Network Security Groups” option under the “Resources.”
On the “Network Security Groups” page, select the “Security group” by clicking on the “Name” as a link to access the security group.
On the “Network Security Group Details” page, under the “Security Rules” check if TCP port 25 for “SMTP” is open to the public.SMTP should be restricted to known IP addresses.
Repeat steps number 2 - 6 to check other “Security Groups” in the account.
Navigate to “Virtual Cloud Networks” under the “Networking”, click on the “Name” as a link to access the “Virtual Network”, select the “Security Group” in which TCP port 25 for SMTP needs to restrict to known IP addresses.
On the “Security Rules” page, click on the checkbox of the “Ingress” and click on the “Edit” button at the top to make the changes.
On the “Edit Rules” page, enter the “IP Address” as per requirements under the “Source CIDR” and click on the “Save” button to make the changes.
Repeat steps number to restrict TCP port 25 to known IP addresses.