Shaun,
SmarterMail has three different levels of throttling: domain, user, and mailing list.
Domain throttling is applied to all remote delivery messages. Throttling settings for the domain level are managed by the system admin and can be configured on a per-domain basis. From the Domain Defaults page, they can be propagated to multiple domains. Based on your initial post, I suspect that this is the limit you are setting to 2000.
User level throttling is applied to all remote delivery messages that are sent directly from a user. This throttling level is managed by the domain administrator. The user level throttling can also be propagated from the User Defaults page. If you are looking to have more restrictive throttling for users and not for mailing lists, You would want to modify the setting in the User Defaults so that it will automatically be applied to any new accounts, and then propagate the new limits to existing users.
Mailing list throttling is applied to all remote delivery messages that are sent by a mailing list. As with user throttling, mailing list throttling is configured by the domain administrator for each individual mailing list. Based on your original post, you may want to check the individual mailing lists and make sure that their throttle limits are set appropriately.
Andrew Barker
Software Developer
SmarterTools Inc.
www.smartertools.com