Why do mail server care about how long a line is? Why don't they just let the client reading the mail worry about wrapping the lines?
For example, the PDP-11 (early 1970s), which was shared among dozens of concurrent users, had 512 kilobytes of RAM. The VAX-11 (late 1970s) might have as much as 2 megabytes.
Programmers were literally counting bytes to write programs.