After years of working as a successful carpenter and builder, Mullen took a position as a part-time rural mail carrier in June 1986. He delivered mail in the Black Oak and Caraway area. In May 1996 Mullen became a full-time carrier and has remained in that position through February.
"I have really enjoyed working for the postal service," Mullen said. "You never know when you go into something how much you will like it, but this job just fit me."
"I have seen things go full circle around me," he said. "I built Gena Alberda's house and now she is the Postmaster at Monette. I took George Brown's job when he left, and now his daughter Karen Vaughn will be taking my place when I retire.
"It never ceases to amaze me how much in common all the people in this area have. I have enjoyed knowing the people on my route, and especially the people I have worked with."
Mullen and his wife Barbara live on Highway 139, east of Monette. They are the parents of three children and have four grandchildren. Son Kevin and his wife Kim live in Stuttgart. Daughter Tara and husband John Walker live in Jonesboro. They have a daughter Drew and son Cody. Son Keith and his wife Holly live in Monette and have two sons, Maddox and Kellan.