I don't know if I am in the correct forum, I LOOKED around and ended up picking this one.  I have a Dell desk computer, Intel Core I-5-4460, CPU 3.20GHz, RAM 8.00 GB, System Type 64-bit operating system.  Let me explain how I use Windows Live Mail.  I log on to Comcast, then Comcast mail.  From there I delete what I don't want, then open my Windows Live Mail and everything I want to save goes into that.  I read and compose my emails from there.  The last TIME I sent an email out was Friday, August 4.  Today I WENT to send some emails with and without pictures, they will not go.  The message that comes up is:  Server. 'smtp.comcast.net'
      Windows Live Mail ERROR ID:  0x8007007A
      Protocol SMTP
      Port 587
      Secure (SSL):  No

I called Comcast and was on the phone with them (them meaning about four different people) trying to resolve this, thinking it is a Comcast problem.  We changed incoming and OUTGOING numbers (smtp and something else), rechanged them, rechanged them again and again, and I was then told it is a Microsoft problem.  I can get incoming mail, but cannot send anything out.  Anyone have an idea what is going on?  I did not change anything from last time I sent an email to today when I went to send one.  It was a total shock to me when it kept saying it would not go due to this error.  Any help would be appreciated!