When reached by Channel 2 Action News' Chuck Dowdle, Smoltz said "Is this a joke?"
Smoltz spoke with Dowdle by phone from a volleyball tournament in Alabama.
"I have absolutely no interest in that," said Smoltz.
Linder made the announcement Saturday at the dedication of a new Gwinnett County GOP headquarters.
The nine-term congressman also called into "The Mark Arum Show" on WSB-AM 750. Linder said he started contemplating retirement about two weeks ago.
"I made the decision last Tuesday night and notified my staff Wednesday morning. I told them not to share the news because I planned to make the announcment during a speaking engagement Saturday," said Linder.
Gwinnett GOP manager David Hancock said the announcement, which came at the end of brief speech by Linder, caught attendees off-guard.
"You can't keep doing things forever and I never intended to stay as long as I did," said Linder. "Eighteen years is a long time," he said.
Linder was one of former House Speaker Newt Gingrich's top lieutenants, and most recently has been an advocate for a sales tax to replace the federal income tax.
"I will continue to travel for the fair tax and speak out on it," said Linder.
Linder said he and his wife have built a place in Mississippi.