We need our emails to look good on machines that have Helvetic Neue. So our font stack is:
font-family: \'Helvetica Neue\',HelveticaNeue,Helvetica,Arial,san
This will solve your problem:
<style type="text/css">
table { border-collapse:collapse; mso-table-lspace:0pt; mso-table-rspace:0pt;}
table td {border-collapse: collapse;}
</style>
<!--[if gte mso 9]>
<style>.outlook { font-family: arial, sans-serif; }</style>
<![endif]-->
</head>
<body>
<table align="center" width="95%" cellpadding="8" cellspacing="8">
<tr>
<td class="hide-on-small" align="center" valign="middle" style="border-top: 1px solid #ffffdffffd;border-bottom: 1px solid #ffffdffffd;font-family: 'Helvetica Neue',Helvetica,Arial,sans-serif; font-size: 14px; color: #999999;">
<span class="outlook">Rummy & Bingo Monthly</span>
</td>
</tr>
</table>
</body>
The font-style was separated from the specifically to fix your Outlook problem. - In the head, below any other CSS you may have declared, I added a conditional comment which will only be read by Outlook. Within this comment is a CSS class which will tell outlook that the font is Arial. Therefore Outlook will completely ignore the fact that your using a font that isn't available, thus negating any reason for it to find its own substitution.
Also, pulled out your inline CSS border-collapse declaration because you can just declare that in the head and in the body, give all your tables an attribute of border="0". Instead of writing style="border-collapse:none;" a dozen or more times.