SMITHTOWN, N.Y. (CBSNewYork) — The U.S. Postal Service is investigating dozens of complaints of mail tampering on Long Island.

At least 50 people in Smithtown reported having their mail opened and gift cards and other items stolen from the envelopes since October.

READ MORE: Exclusive: UPS Driver Jumps In To Help Save Teenage Robbery Victim In Chelsea

A woman named Suzanne said 10 days she received two birthday cards in the mail and both had been opened. One was supposed to contain a $100 American Express gift card but it was gone.

READ MORE: Job Hunting? Experts Suggest Keeping Your Resume 'Drop Dead Simple,' Highlighting Numbers & Making An Effort To Reach Out

“That’s not the way it should be.” she said. “It’s a sad world we live in today.”

The Postal Service issued a statement saying, “We are aware of the situation in Smithtown and we are looking in to it.”

MORE NEWS: Tractor Trailer Overturns, Car Goes Over Embankment In Newark

Customers with concerns about their mail should contact the Postal Service directly “so that each incident is thoroughly researched.”