Troubleshooting common attachments issues

If you encounter problems with attachments in Support, use this guide to find solutions to the most common issues.

The article contains the topics below:

I can't upload attachments

I'm required to sign in when opening attachments

I'm unable to download attachments due to potential malware

My attachment is delivered as a link and not a file

My private attachment in a messaging ticket is restricted

I can't upload attachments

When a customer attempts to upload an attachment that is too large, a warning appears in the related ticket comment. This informs you that the file exceeded the maximum file size.

If the user sends a file too large for the plan type, an error message appears, and the file doesn't attach. The system also logs the error in the audit trail as an event. To see the event, view the events of the ticket.

Ensure your file is within the size limits for your plan. Alternatively, Zendesk offers applications, such as the Box app integration, to help share large files. When you send attachments through email, the Multipurpose Internet Mail Extensions (MIME) email encoding expands the attachment size by 33%.

Note:Images work differently. If you use Markdown, you can embed the image into the body of the message. The displayed image must be a public-facing link.

For more information, see Attachment size limitations.

Users are required to sign in when opening attachments

When a user is restricted from downloading the attachment, it's likely because the Enable secure downloads setting is active to ensure an additional layer of security. The user must sign in to their account to have access. You can deactivate this feature if it's not necessary in your workflow. Check if you enabled Private end-user attachments, which requires end users to sign in before they download any attachment. You can view both settings in Admin Center > Objects and rules > Tickets > Settings > Downloads and attachments.

I'm unable to download attachments due to potential malware

Users may send files that pose a risk to the recipient. A Malware detected warning appears, which prevents the download of the attachment.

Zendesk security scanning ensures that incoming attachments are safe to download. If this happens, an admin can override the malware identification.

For more information, see Reviewing potential malware attachments.

My attachment is delivered as a link and not a file

There are two possible reasons why you receive an attachment as a link and not an actual file:

This is a default behavior if you have Standard comment placeholders in your email notification trigger

The Include attachments in emails setting is deactivated

When you turn on Include attachments in emails, the placeholder for rich text comment allows users to upload an email attachment instead of linked attachments.

My private attachment in a messaging ticket is restricted

On messaging tickets for accounts created on or after December 5, 2024, private attachments are only visible to end users and the assignee of the ticket.

Tip: If users can’t upload a specific file type, such as .exe or .zip, an admin might restrict uploads by file type. Zendesk supports controlling which file types users can upload in your account using the Allowed file types settings in Admin Center. You can customize the permitted file types to match your organization’s security requirements. For more information, see Restricting ticket attachments to Zendesk-recommended file types.