dsl.telesp.net.br has no MX records.
Question and response
Question
dig dsl.telesp.net.br. MX
Answer
The response has no answer records.
Authority
dsl.telesp.net.br. 86400 SOA dnsqipbr1.telesp.net.br. root.telesp.net.br. 2010072121 21600 3600 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0