We received this on May 12:
USPS Web Tools will be retiring our RateV3 API later this year (target date: September 28, 2014). We encourage you to upgrade to RateV4 to avoid any disruption in service. For detailed instructions on upgrading to RateV4, please see the RateV4 Transition Guide on the Web Tools siteunder Web Tools Announcements.
To ensure we have the best contact information for you, please complete our four-question contact form by clicking the link below:
Web Tools Contact Form
To receive future Web Tools updates, follow us on Twitter @USPSWebTools. If you have any questions, encounter any issues, or have any feedback, please email us at WebTools@usps.gov.
USPS Web Tools Program Office