For more details on qmail-remove, you may refer to the link below.

http://www.linuxmagic.com/opensource/qmail/qmail-remove

1. You have to install the gcc compiler + libraries

yum install gcc gcc-c++

2. Download qmail-remove.

wget http://www.linuxmagic.com/opensource/qmail/qmail-remove/qmail-remove-0.95.tar.gz

3. Untar the downloaded file.

tar -zxvf qmail-remove-0.95.tar.gz

4. Then do the following.

cd qmail-remove-0.95
make
make install
cp qmail-remove /usr/bin/
mkdir /var/qmail/queue/yanked

To remove emails from specific email address

qmail-remove -r -p "user@domain.com"

To remove bounce email all at once

qmail-remove -r -p "bounce"