39 Miss. Code. R. 1-9-101
When a utility makes a standard filing under RP 9.100(2) or a filing for a major change under RP 9.100(3) or RP 9.100(4), the utility shall concurrently provide written notice of the filing to each affected customer, briefly summarizing the proposed changes in rates. If the utility employs monthly cycle billings, said notification may be included with or printed on bills of regular billing cycles beginning not later than nine (9) days after the date of filing and shall continue with each billing cycle until all affected customers are notified. If the utility does not employ monthly cycle billing, said notification may be included with or printed on the first monthly bill rendered subsequent to the filing date. Alternatively, any utility may notify all affected customers by U.S. Mail, postage pre-paid, within fifteen (15) days after the date of filing. The notice to customers required herein supersedes the notice requirement under Rule 6E of the Rules and Regulations Governing Public Utility Service.
The filing utility shall file a copy of the notice, along with a certificate with the Executive Secretary of the Commission, verifying that notice to each of the utility's affected customers was provided and providing the date the notice was provided.
39 Miss. Code. R. 1-9-101