does mailwasher realy increase your spam/junk?

I seen this happened to my friend.

(I'm also talking about a clean and well maintained pc, its free from viruses, adware, spyware. And I'm not talking about infected pc)

He just get his new computer and a company email address. And he only use it to send and receive email from his two co-worker.. (in which their pc is also in good condition)

In short, the computers are in well maintained environment.

Now the problem:
Few weeks gone by with no spam or junk mail, until one of his friend, recommend him to use Mailwasher.

Few days after using mailwasher, he start getting several spam/junk mail a day.

Then He uninstalled mailwasher, strangely enough, the junk mail decrease quite alot... (he still get 1 or 2 daily)

Yes I know, mailwasher will flag most of the incoming junk/spam email, but the junk mail keep coming more and more daily.

So the question is, does mailwasher give away our email address to someone else? -- or someone have access to their database --

Thank You for any information and possibly clarification on this.

Have a nice weekend and Merry Christmas and Happy New Year