Apple mail vertical blue line to left of forwarded email?

Have an iMac Mountain Lion 10.8.2 using Apple mail. When I forward email I get a blue vertical line to the left of the forwarded mail or if I reply to an email & leave the received email in the replys string, I get a blue vertical line the length of the received mail. In subsequent strings the number of lines increases by one for each in the back of the string. I have tried cutting & pasting but can't get rid of the blue vertical line. With a message that has a number of vertical lines on the left side, I can't delete any of them to simply forward the email clean. How can I rid myself of those annoying vertical lines on the left of the message blocks! It did it on Lion & still does. see example below:

Begin forwarded message:

From:

Subject: Re: A Biblical Explanation

Date: 7 December, 2012 5:21:11 PM AST

To: J

Quoting J
What verticle line???

See the vertical line below - how can you get rid of them?
Never had it on my PC - must be an Apple thingy!
Cheers

On 2012-12-07, at 2:15 PM, wrote:

Quoting :
,
Glad to hear you are happy with your Apple blah blah . I am still a !!!lol
Rebooting does fix everything imo on the Macs.
Cheers,