Receiving much more spam after moving to office 365

Hello

Previously our email service was handled by Postini and it was quite good with the occasional uncaught spam.

But now we are receiving significantly more spam as reported by users. The majority of it is advertisement based and others are phishing attempts and genuine nonsense.

We followed http://blogs.msdn.com/b/tzink/archive/2013/10/09/how-to-create-more-aggressive-bulk-email-settings-in-exchange-online.aspx and noticed a decrease but we are still getting hit. The "bulk mail" option in the content filter is enabled.

What else can we do?

Thanks