The authority said that it sends out reminders about events and projects but never requests personal information or demands payment over email.
"Under no circumstances does E-ZPass Maryland ever request personal information via email," according to a statement from the Maryland Transportation Authority.
Marylanders started reporting the suspicious emails on July 9, the statement said.
Scammers have also targeted residents in Massachusetts, New York, New Jersey and Washington, DC, the Boston Globereports.
If citizens receive the toll payment emails, they should delete the messages. Those concerned about their accounts or who would like to report receiving the message, may contact the Maryland Transportation Authority at 1-888-321-6824.