I thought you said in the original post that you didn't think it was an IWF filter issue
Blocked here also on a 87.x.x.x address
Tracing route to
www.sendspace.com [216.151.186.5]
over a maximum of 30 hops:
1 2 ms 99 ms 99 ms BeBox [192.168.1.254]
2 * * * Request timed out.
3 15 ms 15 ms 16 ms 10.1.0.1
4 16 ms 24 ms 15 ms 10.1.1.94
5 16 ms 15 ms 15 ms 10.1.1.73
6 15 ms 15 ms 14 ms 10.1.1.141
7 15 ms 15 ms 15 ms 10.1.2.114
8 15 ms 21 ms 15 ms 259.ge-1-2-2.mpr1.lhr3.uk.above.net [213.152.232.65]
9 38 ms 23 ms 20 ms above-gblx.lhr3.uk.above.net [64.125.12.154]
10 97 ms 96 ms 97 ms bandwidth-consulting.tengigabitethernet8-3.ar4.nyc1.gblx.net [64.210.29.14]
11 * * * Request timed out.
12 121 ms 121 ms 122 ms 216.151.186.130
13 120 ms 120 ms 120 ms 216.151.186.5
Trace complete.
The above traceroute and the excessive number of 10.1.x.x does suggest an IWF issue again
Be* Unlimited