The Postal Service offers election officials the ability to create a seamless mailing experience for voters by paying for the postage on return Ballot Mail envelopes that are sent back to the officials by the voters. Discuss your reply mail needs with a Mailing Requirements Clerk. Contact the Mailing and Shipping Solutions Center (MSSC) by emailingemailing MSSC@usps.gov or calling 877-672-0007 (select option 2 for mailing requirements). Hours of operation are Monday through Friday, 7 a.m. to 7 p.m. Central Time (closed federal holidays).