So, uhm, you realize that when people reference "exchange logs" that they're not talking about the "johnny connected" .. "oops, johnny disconnected" type of log, right? When people talk about exchange logs they're talking about what is basically a database journal... which unix doesn't have a generic solution for, because unix doesn't have a standard transactional database.

... and I promise you that the mysql binlogs (a rough equivalent, and needed for point-in-time backups, just like the exchange logs) can devour space with the best of them...