For two months in a row, DorukNet's AS 8685 has spammed the most in the January 2013 for Turkey from CBL data. Before that, it was #6 in November 2012 and also #6 April 2011.
In April 2011 the problem was apparently Lethic with a max of 87,852 on 1 April 2011. DorukNet seemed to have a bit of maazben, cutwail, etc. at that time, but very little compared to Lethic.
In November 2012 the problem was apparently Kelihos with a max of 299,873 on 7 November 2012.
This recent DorukNet peak that looks like Mt. Ararat was up to 13,569,282 on 18 January 2013, apparently from darkmailer2. DorukNet is actually improving since that peak, but meanwhile it managed to increase its December spam total of 54,803,032 to 324,544,788 in January 2013.