A client has just set-up an autoresponder and tested it with a gmail account. The system says it sent the email but none arrived. Assuming client error I've just tested it myself with my own gmail account and sure enough no email. Did another test to a hotmail account and that came through instantly.
OK, email has just come though. Maybe a problem at Gmail....although other test emails were getting there immediately :/ Panic over though :)
Email can be a bit like that - we send them all out immediately but they can take various paths to get to the end recipient sometimes.