Gmail classification labels are organization-defined sensitivity markings, not the ordinary labels you use to organize an inbox. A required classification must match the organization’s policy, and renaming a personal Gmail label does not satisfy it.
Check which labels you are allowed to apply
The feature is for work or school accounts whose administrator has created classification labels and granted access. Some labels may be view-only. You cannot change their official names from Gmail.
If a label or required field is missing, ask the administrator or data owner which classification applies. Do not guess a lower sensitivity merely to make Send available.
Apply the classification in the supported interface
On desktop Gmail, compose or reply and use the Classification line below the subject. Select the appropriate label, complete any fields, and apply it. Google’s current guidance allows up to 20 classification labels on a message.
The documentation says you cannot find or add these labels in the Gmail mobile app, and you cannot add, edit, or remove them after a message is sent. Use a supported desktop workflow when classification is required before sending.
Keep classification separate from enforcement
A label communicates or supports a policy; it is not by itself proof that recipients are authorized or that content is encrypted. Workspace data-protection rules may apply labels automatically or act based on a classification.
Google’s current user guidance also says classification labels are not searchable in Gmail like ordinary inbox labels. Do not promise users a label-search workflow intended for a different feature. If sending is blocked after you classify the message, read the exact policy notice and consult the administrator. Avoid removing or downgrading a correct label to bypass a block. Verify the recipient list, attachments, and quoted content before Send, since a suitable label does not repair an incorrectly addressed message.
Browse Gmail & Google Account help
References
- Add classification labels in Gmail
- About DLP for Gmail | Security & data protection | Google Workspace Help
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.