Susan Heifetz was shocked last week to discover that two letters from loved ones were recently delivered to her old apartment — 45 years after they were sent.

One, a birthday card from her parents dated June 27, 1969, was delivered to the current tenant, who tracked down Heifetz.

"I was like, ‘Oh, my gosh,’” Heifetz, who grew up in Sheepshead Bay, Brooklyn, told the New York Post. “He said, ‘I have a letter for you and the only reason I’m trying to find you is because it's postmarked 1969.’”

The card was for her 19th birthday.

"Dear Susan," the card began. "Mazel Tov." It was signed, “Love and kisses, Mamma Molly and Daddy Sam," and it was sealed with a kiss from her mother.

“I said, 'Tell me what else is on the envelope,'" Heifetz told CBS New York. "He said to me, 'On the back is a lipstick mark,' and at that point I started to cry. This was my mother’s thing at the time — to always seal it with a kiss."

Heifetz told the Post she's amazed how well the note was preserved. “Her Max Factor lipstick 45 years later ... it hasn’t faded.”

Both of Heifetz's parents died more than a decade ago.

“I always knew that my parents watched over the family," she told CBS New York. "It’s something else to get something like this. It validates everything."

Three days later, another letter from 1969 arrived at her former address — this one from Sgt. Mark Wolf, an old boyfriend, before he was shipped off to Vietnam.

“Remember me?” that letter, dated Oct. 25, 1969, began.

When Heifetz contacted the post office, workers discovered yet another piece of late-arriving mail: a 1969 birthday card from her brother.

Post office officials told Heifetz they aren't sure what caused the delay.

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