I think your problem may be that certain clients move anchor styles and text to a range and apply style definitions instead.
<a href="/" style="color:black;">hello, world!</a>
becomes
<a href="/"><span style="color:black;">hello, world!</span></a>
Not 100% sure why they are doing this, but it is annoying. Sometimes it changes to something like this:
<a href="/" style="color:black;" href="/"><span style="color:black;">hello, world!</span></a>
But this is still a mixed bag and is changing all the time. Unfortunately, the only way to confirm that everything always looks right is to use an image.
source share