Local Government agencies are especially vulnerable to bogus emails and SPAM:

Bogus emails can be directed to specific departments (such as accounting) and appear to be from within the organization. For example, it would be a simple process to send a bogus email authorizing a refund, fee reduction. Another bogus email could authorize entry into a secure area. Whatever the email content, if it appears to come from within the organization, the users will most likely believe it. The alternative - not believing any email - would severely restrict communication.

SPAM presents its own problems due to the wide differences in user and department interests. Aside from removing the obvious "organ enlargement" products, it would be difficult to globally differentiate that account did not want information on Golf Resorts whereas Parks and Recreation would.