We are creating the email to send to users.
We need to add a vertical spacer in a HTML table.

We have this:

<td height="15px" style="height:.985em; line-height:.985em"> </td>

and i suggested to use this:

<td style="height:15px; min-height:15px"></td>

My colleague says that: “Mobile gmail isn’t supporting classes and responsive rules from css only inline. Desktop gmail & outlook (both versions) & apple mail supports classes & some responsive rules”.

I’m I right to say that the CSS height + min-heigh will ok?
Apart from testing it on all the device/OS combinations… there is a way to verify it, at least with 99% accuracy?