The Mailto Chrome extension can make most webmail services your default mail client in Chrome. If you want to use a service other than Gmail, install the Mailto: extension from the Chrome Web Store.

You can create HTML-based email templates within Salesforce to use for your business. The HTML email form can be used to create a custom signature that includes an image.

If you use Microsoft Office Outlook 2010 to manage all emails in your small business, consider creating an HTML email signature.

And they correctly note that this problem could make advanced HTML email trickier for marketers and other people who need or like to use HTML email.