Problems with RaiseSupportRequestAcceptanceTest

java.lang.NullPointerException
at com.dumbster.smtp.SimpleSmtpServer.stop(Unknown Source)
at com.atlassian.confluence.SupportRequestAcceptanceTest.testWhenMailServerConfigured(SupportRequestAcceptanceTest.java:114)

Most likely caused by failure to start / stop the mail server (as with other acceptance tests).