Add MSO-specific styles and if/endif table markup

[UTCGilligan]

See Cloudflare email template for example.

• https://info.cloudflare.com/index.php/email/emailWebview?aliId=j05ZccDGIwgO4hEQi5r0Q8GO%2BFy5H%2BDcz9EKeJeSv6dIpToBEYy%2BSw%3D%3D&email=NzEzLVhTQy05MTgAAAGVR8BIDXoZXMqxKTF3_usCDZOc6q7AGQRHenJdW-RM6vCZMokqMkd6XOXF-zrN1c2Xlg5G2r7b6Jbd_QsfDm7cl39F_SM6NP4kIg