Best practices

This section contains Belgacom's best practices for e-mail senders. Although following this these guidelines does not guarantee that your e-mail will be delivered and/or accepted, it should decrease the incidence of your e-mail being misidentified as Unsolicited Bulk E-mail (spam).

Technical requirements

  • Sender is expected to comply with all technical standards for the transmission of Internet e-mail, as published by The Internet Society's Internet Engineering Task Force (IETF), including RFC 2821, RFC 2822, and others.
  • After given a numeric SMTP error response code between 500 and 599 (also known as a permanent non-delivery response), the sender must not attempt to retransmit that message to that recipient again.
  • Sender must not open more than 4 simultaneous connections to Belgacom inbound e-mail servers without making prior arrangements.
  • The mechanism for unsubscribing, either from individual lists or all lists hosted by the sender, must be clearly documented and easy for recipients to find and use.
  • Connections from dynamic IP space may not be accepted.
  • E-mail servers must be secured to prevent unauthorized or anonymous use.
  • E-mail servers must have valid reverse DNS records.