Microsoft acknowledges that users of Outlook on the web may currently experience issues sending emails with attachments. The company is working on a solution. It is not clear how many users are affected by the problem or what causes it.
Those affected will see the error message ‘Error code 550 5.7.520 Message blocked’ when they try to send an email with an attachment, BleepingComputer notes. Microsoft acknowledged in a blog post that there may have been problems with emails with attachments since Monday, November 6, but did not reveal any further information about the problem.
The company does share a workaround for those affected, namely sending attachments as OneDrive links. This can be done via Outlook.com by pressing the usual ‘Insert’ button, choosing ‘Attach file’ and clicking on the ‘OneDrive’ option. If a file has not yet been saved via Microsoft’s cloud service, users can do so first in the Outlook client by choosing ‘Upload & Share’. Alternatively, Microsoft says users can directly paste a link to a file in a cloud service into an email.