Part of email content in native Mail app doesn't resize when orientation changed

Hi,

We have created an HTML and it was pasted in a email template. When that email template send out to me, initially opened it up via native Mail app and the orientation is potrait, the email content resizes correctly. However, when I changed the orientation to landscape, the part of the email content didn't resize accordingly and even when I changed the orientation back to portrait.

In addition, when I opened up the email via native Mail app and the orientation is landscape, the email content resizes correctly and even when I change the orientation to portrait. Everything is fine.

I am not hard core front end/mobile developer so please bear with me.

Thanks!

Marvin