Hotmail and Gmail use blacklists of entire subnets for a single involved IP? Unbelievable

A mail to me from Leaseweb:

Dear sir, madam,

It appears you are hosting a TOR node on your LeaseWeb IP address [omissis].
This has resulted in the block of a (part) LeaseWeb IP subnet. (/24)
As the subnet is added on the SECTOOR blacklist (http://www.sectoor.de/tor.php) this is affecting customers in the same range as yourself.

The SECTOOR blacklist is e.g. implemented by Hotmail, Live and Gmail. This results in other customers not being able to longer use the mail services of these companies.

[omissis details]

Therefore, we kindly, yet urgently ask you to disable the connection to the mentioned ports within 24 hours. Failure to comply and respond (confirm) to this warning, will result in a block of your involved IP address(es).

Thank you for your co-operation and understanding.

Kind regards,

[omissis]
Team Manager Abuse Prevention
LeaseWeb Global Services B.V.