SharePoint Foundation 2010 Outgoing Email settings problem

Hi there,

My SharePoint foundation server has developed a really odd fault, and no amount of searching seems to have given me any answers.

I'm running SharePoint Foundation 2010 on SBS 2011, and it's currently sitting at version 14.0.6137.5002 (April 9, 2013 Security Update).

The situation arose when I created a new workflow to send an email notification.  The workflow failed with the following message:

The e-mail message cannot be sent. Make sure the outgoing e-mail settings for the server are configured correctly.

So, I've checked in Central admin, and it says that SharePointSMTPServer is not configured.  I've checked the settings and they're ok.  I've tried changing the outgoing server name to another server on to another smtp server, but I just get the same 'Not Configured' message.

Email has worked recently as I'd built a test workflow a month or so ago and that was working.

There are no errors in the Event Log or the SharePoint ULS, so I'm stumped

I don't know if it's an update which has knocked the functionality out, but I really could do with getting to the bottom of it.

Has anyone out there experienced anything similar and can suggest some options?

Many thanks in advance.