My company email (sent from outlook pc) signature has social media icons at the bottom - images hyperlinked to facebook, twitter etc. The hyperlinks work perfectly when opened up on PC's and other android and windows based smartphones.
However, when received on an iPhone - tapping an image only allows you to save the image and the hyperlink isn't working.
The files are PNG's and have had nothing different done to them.
The user who created the sig said that it was created through the option within Office 2010.