Web Services Email+ was unable to send out emails earlier today due to falsely identified phishing attempts.
The issue began around 8am and was resolved a little after 12pm. CITES was able to solve the below issue.
This was the original issue cited by CITES on the CITES status page.
ISSUE: Email will not Send. Phishing error message displayed.
The Campus Email Relays have begun suffering a processing error on filtering that is causing large volumes of email to be 'deferred'. Sending servers will see the 'try again later' response, although some applications are unable to handle that SMTP response. This appears to have begun in small amounts at 8am and increased gradually in scope. Complete scope and root cause are currently being researched and a support call with the software vendor is underway.