When you file emails into NetDocuments from Outlook, two tools are doing the work: ndMail and ndSave (part of ndOffice).
They behave differently, and understanding the difference is the key to understanding why deduplication sometimes works the way it does — and why duplicates occasionally slip through.
How Each Tool Files Emails
ndSave saves emails as .msg files.
ndMail saves emails as .eml files.
That distinction matters more than it might seem, especially now that NetDocuments has extended deduplication logic to cover .eml files.
What NetDocuments Looks At to Detect Duplicates
NetDocuments uses two criteria to determine whether an email is already in the system:
- Unique Message ID
- NetDocuments Security (cabinet/workspace access)
When Deduplication Happens
The timing of the dedup check is different for each tool:
- ndMail checks for duplicates before filing. When you click on an email in Outlook, ndMail immediately queries NetDocuments to see if that email already exists. If it does, your filing options will be grayed out.
- ndSave checks for duplicates during the filing process. Once you click File, it looks for a matching document. If it finds one, it won’t save again.
How the Tools Handle Each Other’s Files
Because ndMail and ndSave use different file formats, cross-tool deduplication is handled explicitly:
- If you file via ndSave first, then try to file the same email via ndMail, the ndMail options will be grayed out — it sees the existing .msg and blocks the .eml.
- If you file via ndMail first, then try to file the same email via ndSave, you’ll get a warning, and the save will be blocked.
- If you file via ndMail and try to file again via ndMail, the options will be grayed out — same result.
- If you file via ndSave and try to file again via ndSave, it will appear to process, but the duplicate will silently not be created in NetDocuments.
How to Accidentally Create Duplicates
Despite the dedup logic, duplicates can happen in two scenarios:
1. Manual drag-and-drop. If you file an email through ndMail or ndSave and then manually drag that same email into NetDocuments, it will create a duplicate. The dedup logic only applies to the ndMail/ndSave tools — it doesn’t intercept direct uploads.
2. Filing through both tools within the same second. If you file via ndSave and then immediately (within about one second) file the same email via ndMail, ndMail may not yet see the ndSave upload in NetDocuments. The dedup check passes, and a duplicate is created. This is a timing issue: ndSave hasn’t finished uploading before ndMail runs its check.
New: DeDupeEML Registry Key for .eml Deduplication via ndMail
NetDocuments has extended deduplication to cover .eml files, but it requires a registry key to be set on each workstation.
Registry Setting
Key name: DeDupeEML Location: Computer\HKEY_CURRENT_USER\SOFTWARE\NetVoyage\NetDocuments or Computer\HKEY_LOCAL_MACHINE\SOFTWARE\NetVoyage\NetDocuments Type: REG_SZ Value: True
If the key exists in both HKCU and HKLM, the HKLM value takes priority.
What This Setting Does
With DeDupeEML set to TrueDeduplication logic is applied to .eml files in addition to the existing .msg deduplication. The logic checks for both .eml and .msg files of the same email. Here’s how the cross-format logic works:
- When filing an .eml: If a .msg of the same email already exists in NetDocuments, the .eml will not be saved.
- When filing a .msg: If an .eml of the same email already exists, ndOffice will still save the .msg. This is intentional — .msg files may contain attachments that are not available in the .eml version.
Deployment Note
This registry key needs to be deployed to each user’s workstation where ndMail is installed. For firms with centralized IT, pushing it via Group Policy or an RMM tool to HKLM is the cleanest approach, since the HKLM value takes precedence over HKCU.