_spf-a.trendmicro.eu has no MX records.
Question and response
Question
dig _spf-a.trendmicro.eu. MX
Answer
The response has no answer records.
Authority
trendmicro.eu. 21600 SOA sjc1-tmns1.sdi.trendnet.org. dns.trendmicro.de. 2012072094 3600 1800 3600000 21600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0