Routing problems to Microsoft's Office 365
MINOR Closed Broadband and Ethernet
Broadband and Ethernet
Mar 12, 09:00 AM (9 months ago)
Mar 12, 10:29 PM (9 months ago)
2502 / AA2502
    9 months ago by Andrew

    We have had some reports of problems routing to Offic365. We have tried re-routing the traffic via various routes and traffic still fails deep within the Microsoft network. We are trying to contact Microsoft regarding this. This may affect sending of email to Office365/Outlook/Microsft/Hotmail/etc accounts as well as general access of Office 365 services.

    9 months ago by Andrew

    The problem we're seeing is certain * mail servers not accepting connections on port 25 from us when we try send email to them. Luckily the hosts for do work, and we have emailed Microsoft regarding this.

    9 months ago by Andrew

    We have not yet heard back from Microsoft, but we encourage Office 365 customers to report this as a fault to Microsft too. The problem can be seen by attempting connections to the mail servers listed as the MX records for your domain, this will be in the form of * This can be seen doing:

       telnet 25 

    Where 'DOMAIN' is your domain name with .'s turned in to -'s.

    If it fails, it will timeout, with a message such as:
      Unable to connect to remote host: Connection timed out
    If it works, then the message is similar to:
       220 Microsoft ESMTP MAIL Service ready

    9 months ago by Andrew

    Separate to our emails to the Microsoft NOC we've had a 40 minute call with the Office356 enduser helpdesk, and they are investigating further.

    9 months ago by Andrew

    It seems Office365 servers in Dublin are the ones which are not accepting connections from us. These look to have IP addresses starting 213.199.154.x. Where as Office365 servers in the US such as 104.47.46.x and possibly 23.103.156.x are accepting connections from us OK.

    9 months ago by Andrew

    We have been pursuing various channels to speak to staff at Microsoft who are in a position to be able to help - so far it's proving difficult.
    We have been talking to the general Office365 technical support team and team leaders, who after a couple of hours are starting to realise that the problem is one which they can't help with, and are attempting to move the ticket over to a network team.

    9 months ago by Andrew

    Routing is now working again, we believe the problem is due to to routing through one of our routers which we have disabled this evening. We are still investigating the actual root cause of this. We would like to thank the other customers who reported this fault to the Office365 help desk, and do apologise for the frustration and inconvenience this has caused.

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