Considerable research has focused on encouraging responses via the web for address-based samples of the general population. Although response rates for such mixed-mode surveys have been lower than for the postal only mode, this strategy can generate a substantial number of responses via the web. Many public agencies and nongovernmental organizations serve large segments of the public and, consequently, often conduct surveys to identify client needs or assess customer satisfaction. Given tight budgets, public agencies are looking at mixed-mode strategies for surveying the general public or quasipublic populations. When there are multiple types of contact information, survey administrators can use more mixed-mode methods. This study examines the utility of incorporating e-mail addresses into mixedmode procedures for a survey of an agency’s clients. The study uses clients who have received information from the Cooperative Extension Service to analyze how implementation procedures and response mode affect response rates and item distributions. The clients form three strata (based on providing contact information for postal address only, e-mail only, and both). For clients with both mail and e-mail addresses, three experimental groups were created, including two mixed-mode groups. I focus the analysis on response rates, as well as explore responses for mail and web modes over the sequence of contacts. I found that when mail and e-mail addresses are used to implement a sequence of e-mail and postal invitations in a mixed-mode design, response rates were lower (53-55%) than those for mail only surveys (66%). On the other hand, administration costs for postage was substantially lower for the mixedmode groups (because 60% of the surveys were completed via the web) and the distributions of the substantive and demographic questions were nearly identical to the postal only group. This study demonstrates the benefit of obtaining e-mail addresses and using them in a mixed-mode survey process.