If your newsletter from an ESP campaign looks fine on a desktop, but the mobile formatting is not showing for some portable devices, it's possible that the issue is caused by how different mobile devices handle the formatting of your newsletter. One common issue is that the email may appear too narrow and sit on the left side of the screen for some iOS mobile devices. Fortunately, there are some steps you can take to fix this problem.
iOS devices may resize your email based on the largest element that forces all the elements to become proportionally smaller. This means that even if the email looks fine on a desktop or some other mobile device, it may appear distorted or poorly formatted on iPhones or iPads.
One solution is to use media queries with iOS devices in your CSS. This allows you to create custom styles that will only apply to devices with certain screen sizes or operating systems. For example, you could use the following media query to target devices with a maximum screen width of 480 pixels in the ESP campaign's custom CSS:
@media only screen and (max-device-width: 480px) {\n\n}
To prevent font enlargement by default on iOS mobile devices, you can add the following lines to your inline CSS:
<style> \n* {-webkit-text-size-adjust: none} \n</style>
Alternatively, you can also control text on a case-by-case basis by adding the following inline CSS:
<font style="-webkit-text-size-adjust: none">\nExample\n</font>