Outlook Horizontal Line is not a full line and is inserted centered- office build 1912

What I provided above and what I've captured here:

are all that I can see under File/Office Account/About Outlook.

I'm sorry I don't understand anything about channels in the context of MS support.  I just buy and install products and hope for the best!

Despite my frustration I do appreciate your ongoing involvement and determination to help.  I will really be glad when I get my Horizontal Line back again as it worked for many years dating back to some earlier Office 20xx.  

By the way, Horizontal Line works fine in my copy of Word 2016.  

Also, while Horizontal Rule and Bottom Border look quite similar, they appear to be quite different beasts, in the sense that Horizontal Line is selectable and deletable in its own right (like a piece of text) whereas Bottom Border can only be turned on and off but can't actually be selected or otherwise manipulated.

In the April Public Update going out today there is a fix for the shortened Horizontal line that we were seeing in 2002 version.  It is fixed in build 12527.20436+.  I am not sure how 2002 increments on Windows 7 but if it can update to at least that version hopefully you will get the fix.

Only thing I know is to go create a new email..... alt, N, H

It creates the horizontal line correct.

Select it, Ctrl +C, go to your email, Ctrl +V

I had to upgrade to Windows 10 for various reasons so I no longer have the problem.  I do have one remaining W7 system but the problem doesn't occur on that one (thankfully).  Thanks for your support.