If you’re unable to attach files from Outlook to NetSuite using ExtendSync for Outlook, the issue is usually related to file type restrictions, role permissions, or how the email is saved.
This guide walks through the most common causes and how to resolve each one.
Common Symptoms
You may experience one or more of the following:
We’ll go through each one below.
Common Reasons & How to Fix Them
🔵 File Types: Is the file supported by NetSuite?
NetSuite only supports specific file types when uploading to the File Cabinet.
If a file type isn’t supported by NetSuite’s API, ExtendSync won’t be able to attach it.
To confirm, refer to NetSuite’s list of supported file types check here.
If the file type is not supported, you’ll need to convert it to a supported type (for example, from an unsupported format to PDF or DOCX) before attaching.
🔵 Permission Issues
Your NetSuite role must have permission to upload files. Request permission from your Netsuite admin.
Documents and Files → Create (minimum)
Full is required if using legacy attachment methods
Allow JS/HTML Uploads (only if attaching
.jsor.htmlfiles)Located under Permissions → Setup
⚠️ NetSuite 2018.2 and later enforce stricter security for
.jsand.htmluploads.
🔵 Attaching from Compose Mode
You cannot attach files to NetSuite while an email is still in compose mode.
Why this happens
Microsoft’s API only allows access to attachments after the email is sent
While composing, files exist only on your local machine
Recommended Workflow
Send the email.
Open it from your Sent Items folder.
Use ExtendSync to attach the email and files to NetSuite.
This is a Microsoft API limitation, not an ExtendSync issue.
🔵 Forgot to Mark the Attachments?
It’s possible to save an email but forget to include the attachments.
Once an email is attached:
NetSuite does not allow editing the message to add attachments later
What you can do instead:
Manually attach the files in NetSuite, or
Forward the email to yourself and attach the forwarded email (NetSuite treats it as a new message)
How to Select Attachments Correctly
Click the paperclip icon next to the record name
Select the files
Click Update Attachments
(Optional) Enable Include Inline Images if needed
🔵 Possible NetSuite Caching Issues
In rare cases:
Files show as fully uploaded
File size appears correct
File cannot be opened immediately
This may be caused by NetSuite caching.
How to Test
Open a private/incognito browser window.
Log in to NetSuite.
Navigate to the file and try opening it again.
If the file opens in incognito mode, the issue is likely caching-related and may resolve on its own (sometimes within 24 hours).
If the file still cannot be opened, contact Support.
Best Practices
Attach files after sending emails, not during compose
Confirm attachments are selected before saving
Use supported file formats whenever possible
Ensure your NetSuite role includes file permissions
Use OneDrive or SharePoint integrations for large or restricted files
Need Help?
If you’re still unable to attach or view files after following these steps:
🔎 Search support.cloudextend.io
💬 Chat with Support (bottom-right widget)
📧 Email cloudextend-support@celigo.com
Please include:
File type and size
NetSuite role name
Screenshot of the error or attachment screen
We’re happy to help you get file attachments working correctly in ExtendSync Outlook.