URL/emal address entered in text email changed blocked::otherURL

in OUTLOOK when I enter a URL or email address in the text part of an email,
I noticed that randomly it is changed to blocked::http://www.otherURLname or
for the email address to blocked:thername@otherURL. Why does this happen?
When I do a "whois" on the link (by right clicking the mouse) I get that
Microsoft does not recognize the name part of the URL. I mean by that if URL
that I entered was www.MYURL.com the message states that "Microsoft does not
recognize "MYURL". HELP HELP because the URL changes to a URL I do not want
to be associated with