As it appears on our Terms of Service:

Unsolicited Email (SPAM) and Bulk Email
HostMySite.com will not host websites which are advertised through unsolicited email, excessive newsgroup crossposting, or off-topic newsgroup posts. What is considered spam is determined at the sole discretion of HostMySite.com. Sites in violation of this policy will be shutdown without a refund of any kind. In addition, any bulk emailing that adversely affects the performance of our shared mailservers will be either discontinued or moved to one of our List Server Plans, depending on the exact volume of messages being sent.

(this can be found at the following url: http://www.hostmysite.com/termsofservice/ )

It should be noted that HMS will rarely, if ever, take negative action against a webhosting client due to a spam-related problem without first contacting the client to make sure they are aware of the issue.

If a client has been contacted, however, and continues to Spam, then their account may be suspended pending a resolution of the issue. This is done to insure a stable environment for all those using HostMySite.com email servers.