Summary
mail2.isol.cz has one IP number , which also has a corresponding reverse pointer.
aix.cz,
yyy.cz,
ksw.cz,
bgq.cz,
fig.cz and at least 100 other hosts point to the same IP.
ksw.cz,
fig.cz,
mdp.cz,
pila.cz,
seep.sk and at least 100 other hosts use this as a mailserver.
isol.cz is a domain controlled by two nameservers at
isol.cz themselves. They are on the same IP network. Incoming mail for
isol.cz is handled by one mailserver also at
isol.cz.
isol.cz has one IP number , but the reverse is
mail.isol.cz.
mail2.isol.cz is hosted on a server in Czech Republic.