#host -t MX domainsender.com >domainsender.com mail is handled by 30 mx3.domainsender.com.
>domainsender.com mail is handled by 0 mx.domainsender.com.
>domainsender.com mail is handled by 10 mx1.domainsender.com.
In my logs file j find:
2005-09-05 11:44:06 H=mx2.xdomainxsenderx.com [1.2.3.4]:48565
I=[212.210.229.6]:25 sender verify fail for <user@???>:
Unrouteable address
If j check by
#telnet mx.domainsender.com smtp
# ..
#receipt to: user@???
250 accepted