FOX News has offered the White House examples of what hundreds of people say were unsolicited e-mails on health care, Barack Obama's presidential campaign or his political organization, Organizing for America, but spokesman Robert Gibbs has declined to respond.

The offer comes after a testy exchange on Thursday between correspondent Major Garrett and Gibbs over the e-mail list.

Gibbs told Garrett on Thursday that he couldn't respond until he saw who received the e-mail because he doesn't have "omnipotent clarity."

Asked whether the White House seeks other pieces of information to identify those who might be curious about health care even though they have never signed up for e-mails or visited the Web site, Gibbs said he would have to see the e-mails to know.

Pressed to explain why he couldn't answer, Gibbs said "Well, I hesitate to give you an answer because you might impugn the motives of the answer."

"Why would you say that?" Garrett asked incredulously.

"Because of the way you phrased your follow up. I'd have to look at what you got, Major. I appreciate the fact that I have omnipotent clarity as to what you've received in your e-mail box today," Gibbs said.

"You don't have to have omnipotent clarity. You don't have to impugn anything," Garrett fired back. "I'm telling you what I got: e-mails from people who said I never asked anything from the White House."

Ending the exchange, Gibbs said, "Let me go someplace else that might be constructive."

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The White House maintains a massive e-mail list as part of its effort to promote its position on pressing issues. On Thursday, senior adviser David Axelrod used the list to send out a "chain" e-mail asking supporters of health care reforms backed by the administration to forward his rebuttal to criticism circulating on the Internet.

The mail offered reasons to support Obama's agenda and tried to debunk what the White House decries as myths in the health care debate.

Axelrod wrote that opponents are relying on tactics including "viral e-mails that fly unchecked and under the radar, spreading all sorts of lies."

"So let's start a chain of e-mail of our own," he said, inviting supporters to forward a message countering claims that Obama's plans would lead to rationing, encourage euthanasia or deplete veterans' health care.

But some people who received the e-mails directly from the White House forwarded them to FOX News and asked how they ended up on the list when they've never been in communication with the Obama administration. Some wondered if visiting the White House Web site automatically places them on an e-mail distribution list.

Click here to watch the Gibbs-Garrett exchange.