Mail deliveries to the Senate have been suspended indefinitely while a bicameral mail task force reviews screening and delivery policies to Congressional offices in the wake of last week’s ricin discovery.

“Mail will not start until … everyone’s concerns have been addressed and met,” said a spokeswoman for Senate Sergeant-at-Arms Bill Pickle.

The ricin was found in the Dirksen Senate Office Building, prompting the closure of all three Senate buildings for several days.

The Legislative Mail Task Force — a bicameral entity created after the 2001 anthrax attacks on Capitol Hill to address mail delivery — reconvened Friday to begin a full-scale review of mail screening and delivery policies.

“They’re going to be reviewing all of the procedures, from beginning to end,” said one Congressional source. “Everything is on the table if it means that the mail system can be improved.”

At a press conference last week, Senate Majority Leader Bill Frist (R-Tenn.) said the task force will “look at where mail is opened and how it is opened.”

The group, chaired by the House’s Chief Administrative Officer and the Senate Sergeant-at-Arms, also includes the White House Office of Science and Technology Policy, the National Institute for Occupational Safety and Health, the U.S. Postal Service and the Office of the Attending Physician.

Bush administration officials declined to elaborate on the likely direction of the task force, but a source knowledgeable with the process said the task force will likely focus on the screening and elimination of toxins rather than biological threats such as anthrax, which were at the heart of discussions following the group’s creation in 2001.

“At the time then, there was a lot of focus placed on the irradiation process — which is designed to kill live organisms that might be injected into the mail process,” the source said.

The initial review aimed to prevent mail contamination on a variety of levels, from the U.S. Postal Service and package delivery services such as UPS and FedEx to basic safety procedures such as using latex gloves when handling mail.

“For the most part they’ve done quite a lot of the things that are out there to do with regards to [mail safety] procedures. We were pretty comprehensive the first time through,” the source said.

The discovery of ricin in Frist’s personal office in Dirksen last week prompted the Capitol Police, assisted by the Marines and Coast Guard, to conduct environmental tests and collected thousands of pieces of unopened mail.

Both the Hart and Russell office buildings reopened Thursday, and a Capitol Police spokeswoman said Dirksen is expected to open today.

Some Senate staffers questioned the quick reopenings — Hart opened about a half-day ahead of the schedule Frist announced Wednesday — when at least four offices reported finding uncollected mail in their suites.

“We had boxes of unopened mail in the mail room that had not been removed,” said Chris Lisi, communications director for Sen. Mark Dayton (D-Minn.).

Lisi said the Senator, whose office is in the Russell Building, dismissed his staff for the afternoon after contacting the Capitol Police to report that “it didn’t look like anyone had touched anything.”

The mail had been removed when the office opened Friday morning, but staffers questioned why the building had not been more thoroughly checked.

“Why not keep us out for another half a day? What’s the big rush?” asked Lisi. “We’d much rather do that than rush back here and feel a little strange, a little uncomfortable.”

A Capitol Police spokeswoman, Sgt. Contricia Sellers-Ford, acknowledged several offices contacted the department to collect additional mail but said no offices had actually been skipped.

She said the uncollected mail did not meet “special specifications” issued to the collection teams. Sellers-Ford could not elaborate on the specifications, citing security concerns.

“When staffers resumed regular business, there was mail that wasn’t collected,” Sellers-Ford said. “For whatever reason, they didn’t want it there or felt it was suspicious.”

Aides to Sens. Evan Bayh (D-Ind.), Pete Domenici (R-N.M.) and Ron Wyden (R-Ore.) also confirmed finding unopened mail in their offices.