Office 365 email conks out twice within a week

Microsoft's Office 365 service has suffered two email outages within a week of each other that affected some customers in North and South America that stemmed from different causes but ended in the same result: failed email delivery.

The first outage Nov. 8 stemmed from an overwhelmed antivirus engine and the subsequent backup that caused the service degradation. The second on Nov. 13 resulted from the failure of unspecified network elements, routine maintenance and increased load that combined to degrade service, according to the Office 365 blog posted by Rajesh Jha, the corporate vice president of Microsoft's Office division.

HELP: 11 (FREE!) Microsoft tools to make life easier 

NEWS: AT&T offers Microsoft Office 365 

He didn't say how many customers were affected or where they were located other than somewhere on the two continents. Both outages affected just Office 365 Exchange Online mail services.

Affected customers are entitled to a service credit. Jha apologizes and promises a post mortem on the outages as well as an update on how the Office 365 service level agreement was affected.

The Nov. 8 incident started when an antivirus engine bogged down as it processed emails that the engine determined carried a particular virus. That delay processing emails led to retries that further bottlenecked email flow including legitimate emails, he says.

The issue was resolved by intercepting the tainted messages and quarantining them directly.

To head off similar problems down the line, the company has set a lower threshold for diverting problem emails and implementing faster remediation tools. It is also adding unspecified safeguards that automate remediation of this type of problem, Jha says.

The second incident Nov. 13 started with some scheduled maintenance that required shifting some of the load out of those data centers undergoing maintenance. During this work unspecified network elements failed but sent no alerts of their failure, he says. And finally the entire infrastructure was handling more traffic from new customers, all of which resulted in some customers being unable to access email services.

Traffic for affected users was shifted to healthy data centers while the issues were dealt with.

Jha says the company is in the midst of increasing capacity and is automating how equipment failures are handled to speed up recovery time.

In addition, the company is reviewing its processes to head off future outages.

"As I've said before," Jha blogs, "all of us in the Office 365 team and at Microsoft appreciate the serious responsibility we have as a service provider to you, and we know that any issue with the service is a disruption to your business - that's not acceptable. I want to assure you that we are investing the time and resources required to ensure we are living up to your - and our own - expectations for a quality service experience every day."

(Tim Greene covers Microsoft for Network World and writes the Mostly Microsoft blog. Reach him at and follow him on Twitter!/Tim_Greene.)

Read more about wide area network in Network World's Wide Area Network section.

Join the CSO newsletter!

Error: Please check your email address.

Tags unified communicationsOffice 365 mail outageE-mail servicesMicrosoftat&tNetworkingsecurityOffice 365 outageMicrosoft Office 365Office 365 Exchange outage

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by Tim Greene

Latest Videos

  • 150x50

    CSO Webinar: Will your data protection strategy be enough when disaster strikes?

    Speakers: - Paul O’Connor, Engagement leader - Performance Audit Group, Victorian Auditor-General’s Office (VAGO) - Nigel Phair, Managing Director, Centre for Internet Safety - Joshua Stenhouse, Technical Evangelist, Zerto - Anthony Caruana, CSO MC & Moderator

    Play Video

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

More videos

Blog Posts

Market Place