i dont understand this lines in exim mainlog , may anybody explain this ? my server is sending spam and i need to stop it.
2015-04-25 07:51:42 1Ylqf0-0000TF-G1 DKIM: d=mandrillapp.com s=mandrill c=relaxed/relaxed a=rsa-sha256 i=@mandrillapp.com t=1429909592 [verification succeeded]
2015-04-25 07:51:42 1Ylqf0-0000TF-G1 H=mail134-14.atl141.mandrillapp.com [198.2.134.14] X=TLSv1:DHE-RSA-AES256-SHA:256 temporarily rejected DKIM : DKIM: Deferred. reason='pubkey_unavailable'
2015-04-25 07:51:23 H=www4153up.sakura.ne.jp (todaygoh**.com) [153.121.54.***] sender verify defer for <lixia@cq-l-tax.gov.cn>: host lookup did not complete
2015-04-25 07:51:23 H=www4153up.sakura.ne.jp (todaygoh**.com) [153.121.54.***] F=<lixia@cq-l-tax.gov.cn> temporarily rejected RCPT <info@mhostedsite.com>: Could not complete sender verify
2015-04-25 07:51:23 H=www4153up.sakura.ne.jp (todaygoh**.com) [153.121.54.***] incomplete transaction (RSET) from lixia@cq-l-tax.gov.cn
please note these sites is not hosted in my server