mx.1and1.fr has four IP numbers. All of them are on the same IP network. mx02.1and1.fr, mx01.1and1.fr, mx.schlund.de, mx01.1and1.es, mx00.1and1.es and at least 42 other hosts point to the same IP. 1and1.fr is a domain controlled by two nameservers at 1and1.fr themselves. They are on the same IP network. Incoming mail for 1and1.fr is handled by three mailservers at schlund.de. All of them are on the same IP network. 1and1.fr has one IP number. mx.1and1.fr is hosted on four servers in Germany even though the hostname implies France.