Start with this check.
Attach a small, non-confidential file to a new draft. If it works, compare the original; if it also fails, try another supported browser and record the exact warning.
Do not rename extensions or disable protection to bypass a block. Do not make a private Drive file public merely to fix access. Keep the original and draft.
Which situation matches yours?
Let’s go step by step.
0 of 5 checks completedMark each check to keep track during this visit.
Record where the process stops
Write down the exact error and check for an upload bar, a Drive link or a block notice. Open the original file on the computer to verify it is still available.
If you only have a reference to a file no longer stored locally, obtain an accessible copy first.
Compare a small file
Prepare a test document without private information and add it to a new draft. You do not need to send it. Compare the original while keeping the account and browser unchanged.
If the small file attaches but the original does not, general connectivity alone is not enough to explain the problem. Review the file and warning.
Separate a size limit from a block
Check the limit applicable to your account and Google’s blocked file types. Work accounts may have administrator rules. Compressing or renaming a file does not turn blocked content into permitted content.
A security notice needs a review of the file and its origin. Do not treat it as merely a stalled progress bar.
Isolate browser and network
Keep your draft and try the same test file in another supported browser. If both fail, compare another authorised connection. At work, report attachment failures before changing proxy settings or protections.
A different result between browsers or networks narrows the investigation without deleting cookies for every account.
Check access when using Drive
For a Drive link, review who can access the file and their permission level. Confirm the recipient address. Ask them to test with the authorised account and use restricted sharing for private documents.
Email delivery does not establish file access. The useful confirmation is that the intended person can open the file.
When to stop and ask for help
If a test file fails in two browsers and on two networks, keep the warning, time and storage status for support. If your organisation prohibits sharing it, request an authorised method instead of bypassing restrictions.
Does a step differ from what you see? →Common questions
Does a ZIP avoid Gmail blocks?
It is not a guarantee. Gmail also checks content types inside archives.
Is the size limit identical for every account?
Check current documentation and administrator rules for work accounts. Do not assume every service has the same limit.
Will deleting emails fix a recipient’s Drive access?
It will not correct an access permission. First check that the file is shared with the right account.
Sources and review
Project owner: Eudald Ferrer Ibáñez. Report a correction.
This guide uses official documentation and our own troubleshooting sequence. Menus may change between versions. Documentation reviewed on September 28, 2026; practical device testing is still pending.
How we review and correct guides →Have you identified the problem?
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