Great question - the way we have to manage notification preferences on the new community is confusing, and I know the Marketo team is working on it. In the meantime, here are the basic steps to ensure you receive MUG updates.
On the Portland User Group homepage, click on the "Following in" box in the top right and make sure you are following the group in at least one of the two streams:
The "Following" option will give you updates in the Following stream, which you can access via the My Stuff dropdown menu > My Streams. The "Inbox" option will send notifications to your Inbox in the Marketo Community.
In order to get notification emails, you will need to enable email notifications in your Preferences, which you can access by clicking on your profile pic in the top nav and selecting Preferences. Once there, check the Email boxes for either the "Following" or the "Inbox" option, or both (and any other notifications you wish to receive via email).
In the near future, we may see a new option in the Notification Preferences specific to MUG updates, but for now you will need to follow the group in either "Following" or "Inbox" and then select the corresponding email notification option.
Let me know if you have any other questions, and thank you for bringing this up in the group!