Hi Email Experts,
Is content transfer encoding improves delivery / spam scores / spam filtering? Which content-transfer-encoding is most recommended?

Content-Transfer-Encoding: 7bit
Content-Transfer-Encoding: base64
Content-Transfer-Encoding: quoted-printable

Returnpath.net and few newsletters I received - use "Content-Transfer-Encoding: base64" ---while most esps are using "quoted-printable" and "7bit".