PHPmailer：如何使用base64编码图像发送电子邮件？

When I send emails with php, I receive the content like:

<img
src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAABVYAAAMACAYAAADPPjzCAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAP+6SURBVHhe7N0HfBRl3gfwXzY9IQkt9N6LFBVBsJwIKgooZzu..

Is it possible to integrate base64 images to my email body ? or must I save it to server and then send <image src="//