Please let me know what this means been going on form many months and I keep firewalling these ips

--------------------- httpd Begin ------------------------

10.33 MB transferred in 901 responses (1xx 3, 2xx 540, 3xx 317, 4xx 41, 5xx 0)
370 Images (0.20 MB),
492 Content pages (10.12 MB),
8 Redirects (0.00 MB),
28 mod_proxy requests (0.01 MB),
3 Other (0.00 MB)

Connection attempts using mod_proxy:
137.164.232.15 -> http://lti-mail01.ltinetworks.com:25: 1 Time(s)
198.41.70.2 -> http://lti-mail01.ltinetworks.com:25: 1 Time(s)
198.41.70.90 -> http://lti-mail01.ltinetworks.com:25: 17 Time(s)
206.110.122.251 -> http://lti-mail01.ltinetworks.com:25: 1 Time(s)
206.171.186.2 -> http://lti-mail01.ltinetworks.com:25: 1 Time(s)
206.213.186.99 -> http://lti-mail01.ltinetworks.com:25: 1 Time(s)
216.234.204.6 -> http://lti-mail01.ltinetworks.com:25: 1 Time(s)
24.107.168.20 -> http://lti-mail01.ltinetworks.com:25: 1 Time(s)
63.145.115.195 -> http://lti-mail01.ltinetworks.com:25: 1 Time(s)
66.84.171.50 -> http://lti-mail01.ltinetworks.com:25: 1 Time(s)
75.140.235.10 -> http://lti-mail01.ltinetworks.com:25: 2 Time(s)

Requests with error response codes
400 Bad Request
/w00tw00t.at.ISC.SANS.DFind:): 3 Time(s)
http://lti-mail01.ltinetworks.com:25: 28 Time(s)
404 Not Found
/favicon.ico: 4 Time(s)
http://scifi.pages.at/myproxies/azenv.php: 3 Time(s)
http://www.freeloanpro.net/prx1.php: 3 Time(s)