If you were among the 1.7 million people who got a mysterious, unbidden $91.94 check in the mail recently, you may wonder if it is legitimate. It is! And the best news may be that recipients will get a similar check next summer.

The mass mailing of settlement checks over the past month was the result of a class action lawsuit. The windfall came as a surprise to many because their eligibility was determined automatically without any need for consumers to opt in. A call to the settlement administrator line confirms this is not a scam.

"If you are a class member it is because you bought gas in Oregon from an ARCO or ARCO am/pm gas station using a debit card and were charged a debit card fee," intones a robotic voice on the line.

Years ago, Portland attorney David Sugerman filed the original complaint in Multnomah County Circuit Court against ARCO's parent company, BP West Coast Products, on behalf of drivers who filled up at ARCO stations between January 2011 and August 2013. The following year (in 2014), a jury determined the oil company failed to properly disclose its 35 cent debit card fee in violation of Oregon's unlawful trade practices law. The jury verdict resulted in a penalty of $409 million.

Based on the verdict, the trial court determined that each class member was entitled to collect $200, less attorney fees. After subsequent appeals and a negotiated settlement in which BP did not admit wrongdoing, the final sum worked out to a $185 award per debit cardholder divided into two payments -- one this summer and another next summer.