Graylisting
Graylisting is a way to automatically block spam. It is based on the fact that the behavior of spam software is often different from that of ordinary e-mail servers. If the recipient’s e-mail server refuses to accept the e-mail and signals a temporary error, the sending server must wait and try again later. Spamming applications, however, are usually unwilling to do so.
How can I avoid being graylisted?
- Maintain the good reputation of your IP address
- Use a reliable domain
- Sign your mails with a real name
- Allow immediate unsubscribing
- Format your e-mails correctly (follow the RFC 5322 and HTML standards)
- Don’t use stop words (“Click/Buy/Download”)
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