In college, I worked in the campus mailroom. Sometimes I worked solely in the department mailroom, which was in the basement of one of the primary university buildings. The student mailroom was on the second floor and didn’t really require much talking. You just checked their ID and got the package. But downstairs, people (staff, students working for other departments and professors) would come by to pick up mail. This was ALOT more talking than I expected. I will admit it was very hard at first, but eventually it just became something I didn’t think about, but just did. It definitely helped me with my stuttering and speaking to other people. There were moments where I was caught in a stutter and couldn’t speak, but they became blurry in the larger picture. I hope this helps!