I think what he's saying is that all the mx hosts for aol.com
are not responding on their smtp ports.
Note the attached data that shows the aol mx hosts giving
connection refused on their smtp ports.
wolverine:~> dig mx aol.com.
; <<>> DiG 8.1 <<>> mx aol.com.
;; res options: init recurs defnam dnsrch
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 6
;; flags: qr rd ra; QUERY: 1, ANSWER: 7, AUTHORITY: 3, ADDITIONAL: 3
;; QUERY SECTION:
;; aol.com, type = MX, class = IN
;; ANSWER SECTION:
aol.com. 23h5m58s IN MX 15 d.mx.aol.com.
aol.com. 23h5m58s IN MX 15 c.mx.aol.com.
aol.com. 23h5m58s IN MX 15 b.mx.aol.com.
aol.com. 23h5m58s IN MX 15 a.mx.aol.com.
aol.com. 23h5m58s IN MX 25 b.mr.aol.com.
aol.com. 23h5m58s IN MX 25 a.mr.aol.com.
aol.com. 23h5m58s IN MX 15 e.mx.aol.com.
wolverine:~> telnet a.mx.aol.com 25
Trying 198.81.11.72...
telnet: Unable to connect to remote host: Connection refused
wolverine:~> telnet b.mx.aol.com 25
Trying 198.81.11.31...
telnet: Unable to connect to remote host: Connection refused
wolverine:~> telnet c.mx.aol.com 25
Trying 198.81.11.74...
telnet: Unable to connect to remote host: Connection refused
wolverine:~> telnet d.mx.aol.com 25
Trying 198.81.11.33...
telnet: Unable to connect to remote host: Connection refused
wolverine:~> telnet e.mx.aol.com 25
Trying 198.81.11.81...
telnet: Unable to connect to remote host: Connection refused
wolverine:~> telnet a.mr.aol.com 25
Trying 198.81.19.33...
telnet: Unable to connect to remote host: Connection refused
wolverine:~> telnet b.mr.aol.com 25
Trying 198.81.19.36...
telnet: Unable to connect to remote host: Connection refused
Richard Colella graced my mailbox with this long sought knowledge: