Yahoo messages are no longer accepted by campus mailing lists. Yahoo accounts will still receive mailing list postings but will not be able to post or reply.
Here's why: In mid-2014, Yahoo implemented a DMARC (Domain-based Message Authentication, Reporting and Conformance) "reject" policy that can break campus mailing lists. The anti-phishing policy requires most major email service providers to reject or "bounce" messages that say they are from a Yahoo email address but are coming from somewhere else (in this case, @lists.berkeley.edu). If messages are rejected, email addresses may be disabled from the mailing list.
What to do: If you are currently using a Yahoo account with a campus mailing list, switch to another email service provider, such as a bConnected account or consumer Gmail account. If we are able to resolve this issue we will post an update on this website.