EmbedCopy the following HTML iframe code to your website:<iframe src="https://www.validify.ai/glossary/greylisting/?embed=1&length=X" style="width:100%;height:300px;border:solid 1px black;" class="cm-embedded-content"></iframe>Copy to clipboardA receiving-server technique that temporarily rejects mail from unknown senders (usually with a 4xx code). Legitimate senders retry; spammers often do not.
