By default, Safari on iOS detects any text that is formatted like a phone number and converts this to a link which allows users to call the number by simply touching it. To prevent the auto formatting simply add below meta-tag within the
of the email:
<meta name="format-detection" content="telephone=no">
Additionally if your email contains phone numbers and you do not want to deactivate this function, you can target x-apple-data-detectors using the inherit style to adapt to the surrounding styles and overriding the default iOS ones:
a[x-apple-data-detectors=true]{
color: inherit !important;
text-decoration: inherit !important;
}