It is difficult for me to give you a 150GB file to test, but wanted to check if there are any limits to parsing mbox files? this mbox has about 230K messages, but it fails at about 37K consistently. I broke up the mbox files, and it seemed to no have an issue. But you can understand the pain in opening and parsing a 150GB file maually.
Can you point me to the best way to process and extract individual messages for large mbox files?