Using Canonicalize() To Embed Emoji In Email Subject Lines In ColdFusion

test.cfm

<cfscript>

	// Subject line with a left-arrow HTML entity and an eyes-emoji HTML entity.
	subject = "&larr; Hello, is it me you're looking for &##x1f440;?";

	// Try sending with embedded HTML entities.
	sendEmail( subject );

	// Try sending with canonicalized HTML entities.
	sendEmail( canonicalize( subject, false, false ) );

	// ------------------------------------------------------------------------------- //
	// ------------------------------------------------------------------------------- //

	/**
	* I send a test email with the given subject line.
	*/
	public void function sendEmail( required string subject ) {

		cfmail(
			to = "ben@example.com",
			from = "no-reply@example.com",
			subject = subject,
			type = "text/html",
			server = "127.0.0.1",
			port = 1025,
			spoolEnable = false
			) {

			writeOutput( "<h1> Hello There </h1>" );
		};

	}

</cfscript>