Serious Discussion Some users can't send emails with attachments


Level 44
Thread author
Top Poster
Nov 10, 2017
In a Monday advisory, Microsoft warned users about issues they might encounter when sending emails containing attachments. users impacted by this known issue are seeing "Error code 550 5.7.520 Message blocked" errors when trying to send emails.

"Some users may not be able to send emails that contain attachments from their mailbox," the company said.

Redmond suggested an alternative method that enables affected users to share files: uploading them to OneDrive and sharing the link with the intended recipients.

To implement this workaround, users must click the attachment button while composing their message and click OneDrive to add previously uploaded files or the 'Upload and share' button to add the attachment to their online storage drive.

Alternatively, those affected by this issue could copy the link of an Office or OneDrive file and paste it directly into their email.

Microsoft also provides step-by-step instructions to guide users through this process:


Level 35
Top Poster
Content Creator
May 13, 2017
It is most likely due to the restriction by "forced" onedrive, once it is full, you will receive the message that you will not be able send attachments. For example, I have 110GB onedrive and separate 50GB for attachments, but once I fill onedrive, I will not be able to send attachments, though I will have 50GB free. MS is just trying to force people into buying MS365 and it turned against them.


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ForgottenSeer 100397

Outlook's outlook to 'outlook' for "outlook" to... 🤔... deliver them! WTOutlook! 🤣
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