How do I get MS Outlook to accept the CSS style display:block?

Question

I am composing an HTML email using a service (MailChimp). The way that MailChimp marks up headings is to use a SPAN tag and gives the tag the inline style of

Answer 1

The CSS display attribute is not supported in this version of MS Outlook.

Here's "The Book" on what you can and cannot use:

campaignmonitor.com/css/

Basically, if you can't change your mark-up to a natively-block item, you're stuck.