Email Anti Spam Policy

Dear Valued Customers,

Recently, the lenient filtering and open-port configurations for email transmission on servers hosted at vHost have led to certain customers exploiting the system to send unsolicited spam emails. This uncontrolled activity has negatively impacted and compromised the reputation of all other IP addresses under vHost’s management.

vHost is a Hosting and Cloud service provider holding ASN 56160, delegated by the Ministry of Information and Communications (MIC) / Vietnam Internet Network Information Center (VNNIC).

As illustrated in the example below:

• Level 1: IP 103.27.60.2 is clean and not listed on any spam database.
• Level 2: The /24 IP range (103.27.60.0/24) is clean and not blocklisted.
• Level 3: Blocklisted because more than 50 IPs belonging to the provider owning ASN 56150 have been reported and listed as spam IPs.

According to global network security standards, IP addresses are blocklisted across 3 progressive levels:

• Level 1 (Single IP): Only the specific offending IP address is listed.
• Level 2 (Class /24 Block): The entire /24 subnet (consisting of 256 IPs) is listed. Even if you do not directly send spam, your IP will be affected if other IPs within the same network range are reported.
• Level 3 (Autonomous System Number – ASN): All IP addresses registered under that corporate ASN are entirely blocklisted.

To prevent any negative impact on vHost’s active infrastructure and to safeguard the email delivery services we provide to numerous domestic and international corporate clients, vHost will enforce a strict email blocking policy.
vHost will block all outbound email transmissions across all vHost servers, with the sole exception of dedicated Email Services built, managed, and administered directly by vHost for our customers.

If you require the use of external SMTP servers to send system emails or transactional notifications, please submit a support ticket detailing your requirements for our review and assistance:

• Individuals: Please submit a request for vHost to review and approve the opening of the SMTP port.
  Companies/Enterprises: Please submit a request for vHost to review and approve the opening of the SMTP port.
• Companies/Enterprises: Please submit a request for vHost to review and approve the opening of the SMTP port.

• Individuals: Port unblocking for outbound SMTP is not supported.
• Companies/Enterprises: Please submit a request for vHost to review and approve the opening of the SMTP port.

To request port unblocking, please open a formal support ticket via one of the following official channels:

• Ticket: https://members.vhost.vn/tickets/new/
• Email: support@vHost.vn

Effective Date: This policy officially enters into effect on December 5, 2025.

Sincerely,