If Gmail cannot attach a document from Files or iCloud Drive on your iPhone, first check whether the document opens in Files itself. Gmail cannot upload a file that its storage provider cannot supply.
Locate a usable copy of the document
Open Files and browse the location containing the document: On My iPhone, iCloud Drive, or a connected cloud-storage provider. Search by filename if necessary. Open the file and let any download finish while you have a working connection.
If a third-party location is missing or asks you to sign in, resolve that with its own app or your organization’s support team. Do not move a confidential work file to a personal cloud account just to make the picker display it.
Attach through Gmail’s Files option
In Gmail, start or reopen the draft, tap Attach, and choose Files. Navigate to the verified document rather than choosing Photos or Google Drive by mistake. Wait for the attachment to finish uploading before treating the draft as ready.
Personal Gmail has a 25 MB total attachment limit; work and school accounts can have administrator-defined limits. Gmail may substitute a Drive link when the total exceeds the applicable limit. A link also requires appropriate sharing permissions, so it is not automatically equivalent to an attached copy.
Identify the failing stage
If the picker closes but the document never appears, try a small, harmless local test file. If that works, compare the original file’s availability, size, and storage provider. If no file uploads, update Gmail and test the connection.
A security block or company policy needs a different response from an unavailable iCloud file. Do not rename a prohibited executable to evade Gmail’s checks. Keep the original draft, note the exact error, and ask the relevant provider or administrator about that specific file and destination. Avoid repeated Send attempts until you know whether an earlier attempt succeeded.
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References
Reviewed against the linked product guidance, standards, and identified vendor or public-authority guidance on October 29, 2026. Available options and screen labels can vary by account, device, region, and organization policy.