In order to help ensure prompt and successful email delivery without it being throttled or flagged as spam, we do not allow bulk mail to be sent from our mail servers and we do not support the automated sending of email (eg. web forms or transactional receipts).
We consider bulk mail to be mail of identical or similar content sent to 250 or more addresses external to the Rackspace network. This also includes the sending of the same or similar message more than 250 times to a single external email address (eg. a monitoring alert system). Breaking up mass mailings and sending them in smaller batches to intentionally avoid this restriction is also a violation of the AUP.