Microsoft just reached a new corporate milestone — but not the good kind. The Redmond, Washington-based tech giant is set to offer voluntary buyouts to a portion of its U.S. workforce, CNBC reports. That might not be a big deal for many companies, but this is the first time Microsoft has tried to cut headcount in this way since the company's founding 51 years ago. In order to be eligible, an employee must be at the senior director level or below, and their age plus years of employment need to add up to at least 70. The program also excludes anyone with a sales incentive plan. The details of the buyout package remains unknown, but reportedly people who are eligible will hear more on May 7. Mashable Light Speed “Our hope is that this program gives those eligible the choice to take that next step on their own terms, with generous company support,” chief people officer and executive VP of Microsoft Amy Coleman said in an employee memo obtained by CNBC.…