We have exactly the same issue in Cyrus IMAPd. That said, we have a test for it during configure, and either compile with full mmap support or with dodgy fake

We have exactly the same issue in Cyrus IMAPd. That said, we have a test for it during configure, and either compile with full mmap support or with dodgy fake mmap support (which is shit - it just reads the entire file into real memory every time)