The post office might not always be the swiftest when it comes to getting letters delivered on time, but that doesn't mean it won't eventually deliver the letter. Even if it's almost half a century later.

The New York Post says Susan Heifetz from Brooklyn, New York, was shocked when she received a letter her now-deceased mother had sent for her 19th birthday — 45 years ago.

The letter was delivered to Heifetz's childhood home last week, and the current tenant tracked her down. Heifetz told CBS she was skeptical at first and asked what else was in the envelope.

"At which point he said to me, 'On the back of the envelope is a lipstick mark.' And at that point, I started to cry. This was my mother's thing at the time to always, you know, seal with a kiss."​ (ViaCBS)

When asked why it took the post office so long to deliver the letter, a spokeswoman told The Brooklyn Paper the letter had probably just been put back into the mail recently after having been delivered to the wrong person years ago.

But the story doesn't end there. In the days following, Heifetz received two more letters that should have been delivered to her 45 years ago.

New York Daily News says one was a letter from her then-boyfriend, who was serving overseas in Vietnam. The second was another 19th birthday card from her brother, Barry.

Heifetz told CBS she takes the delivery of these letters as a sign that her loved ones approve of her decision to move from Brooklyn to be closer to her brother in Las Vegas.