There are lots of emails being circulated about how much money and
other benefits United States Senators receive upon retirement. 
Apparently they are not constrained by the Social Security laws that
the remainder of the population is subject to.  I'd like to know from
a reliable source (and I'd like to know who or what the source is)
just what these Senators actually receive upon retirement from the
Senate.

I, too, have received numerous forwarded emails which described the
supposed riches being collected by members of Congress upon their
retirement. I was shocked by the statement that Senators and members
of the House of Representatives do not have to pay into the Social
Security system. I did a little checking on this several months ago,
and found that many of the "facts" offered by the email were either
outdated, based upon misunderstandings, or totally false.

Here are two websites that offer excellent discussions of
Congressional pensions:

C-SPAN
http://www.c-span.org/questions/weekly68.htm

National Taxpayers Union
http://www.ntu.org/links/FAQs/CongressionalpayperksFAQ.php3

Several online "debunking" sites have discussed this matter in detail.
For reasons of copyright, I am posting only brief excerpts here. You
may want to click the link below each excerpt and read the full
articles, which are quite interesting:

"Federal civilian employees, including members of Congress, were
covered by Social Security by P.L. [Public Law] 98-21 in 1984. In
addition to the mandatory pension funds FERS or CSRS, members of
Congress and other federal employees can participate in the voluntary
Thrift Savings Plan (TSP) that allows them to save between 5% to 10%
of their annual salary into a tax deferred retirement investment
fund... So what do Congressional retirees get from their obligatory
pensions? As of 1998, the 400 odd retired Congressfolk averaged an
$50,616 for those covered by CSRS or $46,908 for those covered by
FERS."

Urban Legends
http://www.urbanlegends.com/ulz/ss.html

"It is not true that Congressmen do not pay into the Social Security
fund. They pay into the fund just as everyone else does. It was true
prior to 1984 that Congressmen did not pay into the Social Security
fund because they participated in a separate program for civil
servants (the Civil Service Retirement System, or CSRS), but that
program was closed to government employees hired after 1983... Whether
members of Congress participate in the older Civil Service Retirement
System or the newer Federal Employees' Retirement System (FERS), their
pensions are funded through a combination of general tax provisions
and contributions from the participants. Right now, members of
Congress in the FERS plan must pay 1.3% of their salary to FERS and
6.2% in Social Security taxes. As of 1998, the average annuity for
retired members of Congress was $50,616 for those who retired under
CSRS and $46,908 for those who retired under FERS."

Snopes.com
http://www.snopes.com/inboxer/outrage/pensions.htm

"It is not true that members of congress don't pay into Social
Security.  It's been required of them since 1983, according to Andrew
G. Biggs, Social Security Analyst for the Cato Institute in
Washington, D.C... Depending on a person's length of service, it is
possible to retire with annual income that is equivalent to a
Congressional salary, but no member of Congress automatically retires
with his or her salary being paid as pension."

Truth or Fiction
http://www.truthorfiction.com/rumors/congressionalpensions.htm

"This message claims that Social Security is not being reformed
because our congressional representatives and senators do not have to
pay into it.  This is not true.  Members of both the house and the
senate having been paying into Social Security since 1983... Many
people in this country have pension plans, 401K's, IRA's and other
plans to help them plan to retire on more than just social security...
The size of their pensions is determined by a number of factors
(primarily length of service, but also when they joined Congress,
their age at retirement, their salary, and the pension option they
chose when they enrolled) and by law cannot exceed 80% of their salary
at the time of their retirement. (Information provided by The San
Fernando Valley Folklore Society)"

Truth Miners
http://www.truthminers.com/truth/social_security.htm

Google search strategy:

Google Web Search: "senators" + "pay into social security"
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=senators+%22pay+into+social+security

Ironically, many of the "hits" you'll get with a Google search are
people quoting inaccurate data obtained from the widely-circulated
email. These days, you can't always believe something just because you
read it in an email or on a website, but some deeper digging often
reveals the truth.

I hope this information is helpful. If anything is unclear, if you
have a question about my research, or if a link does not function,
please request clarification; I'll be glad to offer further assistance
before you rate my answer.

Best wishes,
pinkfreud

Good answer and quick.