I have had the same problem here.  Going round and round with support.  They respond to me (I submit them via the support page) and keep telling me that I need to answer the emails - not create a new trouble ticket.  

WHY don't they read the message I am sending them?

I keep telling them that I CAN'T SEND EMAIL and they keep saying the same thing over and over again.  Make sure your settings are xx, delete and recreate the account, etc.  NOTHING CHANGES.

I can send email to anyone who has an email address on my domain, but outside of that, I am in a black hole.

If it was the Microsoft updates that did it (Internet Explorer and Outlook) how can we un-install them so our systems work again?

Judy

Hi Judy,

I know you are fustrated and so are we

With your help and feedback we will get this resolved.

Yes, what ever your tech did, appears to have fixed the problem for me.   I have been able to send messages outside my domain.

Thanks for all your time,

Judy

It seems that lunarpages is requiring authentication to send outbound emails. Previously, I only needed to check my mail using my credentials and I could then send email (through mail.domain.com), but it seems to be a bit pickier now. It's not a problem, as I'm actually glad this was enabled. It's just too bad that I didn't know it was coming.

Did I mention that these forums are awesome?