Although she won’t be sworn in to the Senate until 12:30 p.m. today, Kirsten Gillibrand (D) wasted no time sending out a fundraising appeal, circulating an e-mail to supporters on Monday.

The brief e-mail, whose subject line reads, “Following a Giant,” thanks donors for their prior support and pays tribute to the woman Gillibrand will be replacing in the Senate, Secretary of State Hillary Rodham Clinton. Then it cuts to the chase.

“As this is an appointment, and a special election follows in just 2 short years, I will need your help and dedication right away,” Gillibrand writes. “With the right resources, I will be able to reach every family in our great state and offer my positive message of service.

“Such outreach will cost a substantial amount of money. I hope you remain, as I do, undeterred by this challenge. I hope you will join me in building a well-funded campaign.”

Gillibrand’s missive comes as Empire State insiders continue to weigh the political implications of her appointment by Gov. David Paterson (D).

Some liberal Democrats and their allies have been critical of the selection, arguing that Gillibrand is too moderate to hold the seat, and Rep. Carolyn McCarthy (D) is threatening to challenge her in the 2010 primary because of her stance on gun control. But others see the upstate Congresswoman as a solid choice, a budding political superstar who will help balance the statewide Democratic ticket in 2010.

Voters, however, are generally positive, even if they don’t know Gillibrand very well — if the first poll since Friday’s announcement is any indication. In the poll, conducted Friday to Sunday by the Quinnipiac University Polling Institute, New Yorkers by a 46 percent to 30 percent margin said they approved of the Congresswoman’s selection. Her favorable to unfavorable rating was 25 percent to 10 percent.

“New Yorkers aren’t unfriendly, but two-thirds of them don’t know much about her,” said Maurice Carroll, director of the polling institute.

The poll of 1,047 registered voters had a 3-point error margin.