Postal Service Provides Mail Handling Safety Tips
The US Postal Service has posted a document called What To Do If You Receive An Anthrax Threat on their Web Site. It takes the form of a Frequently Asked Questions document, and includes criteria that can be used to identify suspicious letters or parcels.
Among the criteria: "{articles} have no return address, or have one that can't be verified as legitimate", and "show a city or state in the postmark that doesn't match the return address". As we stated in our analysis of the appearance of the anthrax-tainted envelopes, the envelopes sent to Tom Brokaw and Senator Daschle both fail these two criteria.