Consider from address to be no-reply@
By default stackspin is mailing for notification from "stackpin@domainname.com", however, it is not always the case a domainname has e-mail configured at all. It would make more sense to use 'no-reply@domainname.com' for notifications. This is better accepted by filters (which sometimes check the existence of an e-mail address) and more clear it is not possible to reply to the email address,