Closure of port 25 and changes in email authentication

Closure of port 25 and changes in email authentication

Important: If your email client is still using port 25 for sending emails or has outdated authentication settings, email sending may stop working.

What should you do? You should review your email client settings and update: the outgoing port (SMTP), the security type, and the authentication method

Check the corresponding guide depending on the email client you use:
  1. Outlook
  2. Mail (Mac)
  3. Gmail
  4. Thunderbird
  5. Android
  6. iPhone
An update has been made to the email service configuration in order to improve the security and deliverability of emails.

This update includes two important changes:
  1. Permanent closure of port 25 for sending emails
  2. Use of standard authentication (normal password) instead of legacy encrypted methods
Port 25 has historically been used for sending emails via SMTP. However, it currently poses a security risk and may negatively affect email deliverability.

Why has it been closed?
  1. Reduces spam sent from compromised devices
  2. Prevents abuse by malware or bots within the network
  3. Improves the security of the email service
  4. Increases delivery rates using modern configurations
New recommended configuration: To ensure secure email sending, it is necessary to update the outgoing server (SMTP) settings:

Option 1Option 2
Port: 587Port: 465
Security: STARTTLSSecurity: SSL/TLS

Changes in authentication (password)

Additionally, the authentication system has been unified. From now on:
  1. A normal password (unencrypted) must be used
  2. It is not necessary to apply legacy encryption methods to the password
  3. Encryption is now handled automatically through the secure connection (STARTTLS or SSL/TLS)


For more information, please contact us.