> ## Documentation Index
> Fetch the complete documentation index at: https://docs.gcore.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Troubleshoot blocked SMTP ports

> Steps to verify and request unblocking of SMTP ports 25, 465, and 587 blocked on Gcore servers for spam prevention.

SMTP ports 25, 465, and 587 are blocked when the system detects unusual outbound email traffic from a virtual server. This is a spam prevention measure.

## Verify the block

To verify whether the ports were blocked, navigate to **Support** > **Support tickets** in the [Hosting portal](https://hosting.gcore.com/billmgr). A blocking notification appears as a ticket with the subject "SMTP ports have been blocked" in the list.

![Support tickets section in the Hosting portal sidebar, showing the empty ticket list](https://mintcdn.com/gcore/bP_M3iNvkCNJWoX1/images/docs/hosting/virtual-servers/troubleshooting/troubleshoot-blocked-smtp-ports/troubleshoot-blocked-smtp-ports-image1.png?fit=max\&auto=format\&n=bP_M3iNvkCNJWoX1\&q=85\&s=6f4a42c1a50bc681781d1954ef42bfab)

## Blocking policy

Per paragraph two (d) of the [usage policy](https://gcore.com/legal), servers cannot be used to send unsolicited emails, chain letters, or spam. Outbound email is restricted to users of services hosted on Gcore servers.

## Request unblocking

[Contact support](/hosting/contact-our-technical-support) and include the details that match the situation:

| Scenario | Provide |
| - | - |
| Legitimate email was sent | The domain name of the service whose users received the mailing |
| No mailing was sent, but blocking notifications appeared | The server setting that caused excessive SMTP traffic and how it was fixed |
| No mailing was sent, no notifications appeared, but ports do not work | Confirm that no blocking notification was received and describe any recent network configuration changes |