E-mail list is coming from one address on behalf of others.

[sbarstow]

I set up our companies email with Plesk 8.1 and set up several lists, one in particular emails everyone in the company. Whenever somebody emails the whole company it says it comes from my address on behalf of the sender.

Is there any way to resolve this so that it says it comes from the sender only?

Any help will be greatly appreciated!

Sean