11/7/2013 Exchange Online - Issues Connecting via Outlook
I have had numerous emails from people regarding this issue, and just in case you are then I thought I would just mention the following as I can see someone has already posted about an IMAP issue and it will be linked.
Microsoft Exchange Online Team are currently investigating reports of some users served out of the EMEA region unable to connect using the Outlook client. Outlook Web Access(OWA) service is not affected at this time. We will be providing further updates as the investigation continues.
At the moment I do not have any further update, but I am keeping in regular contact with the EMEA Support Team. If you wish to monitor the service for updates then please login to your Microsoft Online Services Portal and Click on Service Status and you will receive regular updates their.
I am not 100% sure if this affect's customers who are using Wave 14, but this is definitely an issue for Wave 15 users.
Update, As per my investigations it is related to DNS.
"Microsoft Exchange engineers have found that Outlook services in Exchange are healthy. We are currently troubleshooting the networking and DNS side of infrastructure. Outlook Web Access users are not affected at this time. More updates will be provided at 12.00 PM UTC or upon service restoration."
Jul 11, 2013 12:46 PM Service interruption
Microsoft exchange engineers have confirmed that the O365 Exchange service is healthy at this time. We believe that the issue is caused by a faulty external DNS. Customers are reporting that switching DNS provider is resolving the issue. Customers currently experiencing problems connecting to the service can try to switch to another DNS provider such as OpenDNS(126.96.36.199 and 188.8.131.52) or Dnsadvantage(184.108.40.206 and 220.127.116.11). Next update will be provided at 2:00 PM UTC.