Here's my letter. What does yours look like?
We are writing to notify you that your user account ___ will be disabled in 28 day(s) due to suspiciously high levels of email activity. Due to these concerns, email from this account was initially throttled on 2006-08-07 11:40:56.
IMPORTANT: In order to ensure that the account is not disabled, it is extremely important that you both read and respond to this email with the information requested. Note that if this is a shell/FTP account and you do not respond, associated shell/FTP and web services will also be disabled.
In order to un-throttle your account and prevent its disablement, we will first need to know how much email you need to send and ensure that your usage is consistent with our anti-spam policy. You may review this here:
What we will need to know:
Whether or not you utilize an opt-in confirmation process (not to be confused with regular 'opt-in') for all of your your list's subscribers. This is a process wherein each person who signs up for your list is sent an email after subscribing with a tagged link in it that they must click on before being added to the list. Those who do not click on the link are not added, and receive no further bulk email.
Whether you log each confirmation with the date/time and IP address associated with that confirmation.
Where we may go to independently review your opt-in confirmation logging data.
Where may we sign up for your mailing list in order to test out its opt-in confirmation functionality.
How much many emails you wish to send from this account on an hourly basis.
If your bulk email usage is not in compliance with these policies, we must ask that you cease any bulk email activity immediately until you have become compliant. Failure to do so may result in immediate DreamHost account disablement without warning. The easiest way to ensure compliance is to use our Announcement List feature, which you can access here:
The Announcement List feature handles the opt-in confirmation and logging aspects of the policy for you, so that you don't have to.