Does MIT have a Sender Policy Framework (SPF) record?
SPF is a system that says what IP addresses are allowed to send mail on behalf of @mit.edu email addresses.
Yes, MIT has an SPF record. It is a lenient one. You can use a DNS lookup command to look it up. (Output wrapped for clarity.)
The "ip4" sections mean "mail that is from a @mit.edu address ought to come from the named IP ranges." (Result: Pass. Intended action: accept.)
The "~all" on the end means: "mail from all other IPs is discouraged but not forbidden; it is okay to accept such mail." (Result: SoftFail. Intended action: accept but mark.)