Summary
smtpb1.tf1.fr has one IP number , which also has a corresponding reverse pointer.
tf1.se,
wat.fr,
wat.tv,
jet.tv,
tfou.fr and at least 100 other hosts use this as a mailserver.
tf1.fr is a domain controlled by two nameservers on different IP networks. Incoming mail for
tf1.fr is handled by two mailservers at
tf1.fr themselves. They are on the same IP network.
tf1.fr has one IP number.
smtpb1.tf1.fr is hosted on a server in France.