基本邮件定制功能不足

[Lilly (Lillian)]

你看到这个了吗？不确定它是否适用于你的情况，但可能值得一试

How to make customized emails better looking

You can use something like https://beefree.io/templates/ to create a beautiful email template and then copy the html code into email style, that runs with standard email html.