Dalton, who suffered from cystic fibrosis, received more than 500,000 cards from all over the world before he died Saturday, ABC News reported.
"The cards give him something to look forward to. Something to get excited about," Dalton's mother, Jessica Dingus, said before her son's death.
Cards addressed to Dalton poured in from all over the world; so many that the local post office enlisted the help from volunteers to sort, count and deliver them.
Guinness World Records said it was in touch with the Dingus family before Dalton passed away to discuss applying for recognition, however, the family has yet to make a formal application.
"At this time, there has been no formal record application made with Guinness World Records for this particular attempt, so we are unable to speculate on whether or not it would constitute a new record," Guinness spokeswoman Jamie Panas told ABC News.
"If and when an application is made on his behalf, our records management team could then explore the topic of re-opening a designation for his feat," she said.