Sending, receiving, and organizing email in Outlook.com
Welcome George,
Thank you for providing those details. Since the problem occurs on multiple devices (laptop, tablet, and phone), across different networks, and with very small attachments, this does not appear to be a browser cache issue or a file size limitation.
To narrow this down further, could you please confirm:
- Does this happen with all file types (for example .pdf, .jpg, .docx, .txt), or only certain types?
- Do you receive the same error when you try attaching a file to: a brand-new email, and a reply to an existing email?
- When you sign in to Outlook.com in a private/incognito browser window, does the attachment still fail?
- Approximately when did the issue first begin, and are you able to attach files using another Outlook.com account (if you have one available for testing)?
In the meantime, please try these quick checks:
- Sign in to Outlook and open Settings > General > Storage. Confirm there are no warnings about mailbox storage limits
- In Outlook.com, create a completely new email (not a reply or forwarded message) and try attaching:
- a small .txt file (a few KB)
- a small .jpg file Let us know whether both fail or only certain file types fail.
- If you use any browser extensions (ad blockers, privacy tools, script blockers), temporarily disable them and test again.
- Open Outlook.com and click Settings > Mail > Compose and reply
- Under attachment settings, ensure there are no unusual options enabled.
- Save any changes and test again.
I look forward to your update.