A USPS service that allows customers to prepare and send large amounts of mail. One key to keep in mind is that bulk mail rates start at $0.19 per piece of mail, with a minimum of 200 pieces. A smaller mailing would be charged the retail rate of $0.35 in 2020.
Processed by USPS on a "time available" basis, meaning it should not be used for time-sensitive mail.
Standard mail is the least expensive postage mode.
See "USPS Bulk Mail Rates" https://faq.usps.com/s/article/How-do-I-get-Started-with-Bulk-Mailing