A discrepancy in item count may occur following any mail migration using CloudM Migrate, where emails appear missing in the destination account despite specific indicators suggesting a successful transfer.
The Issue
- CloudM Migrate reported near-zero errors on the account migration.
- The source/destination platform reports approximately the same data volume (GB) in both accounts.
Note: Data size (GB) is not a precise metric for defining item count discrepancies due to compression, metadata, and overhead variations.
Initial Troubleshooting Steps
| Step | Action |
|---|---|
| Verify Discovery & Counts | Check if Data Discovery or Environment Scan was performed pre-migration. Compare pre-migration counts (e.g., 70,335) against batch run processed counts (e.g., 71,700). |
| Confirm Strategy | Ensure the migration utilized CloudM's Recommended Migration Strategy - i.e., a bulk > delta migration flow. If a bulk migration was performed up to a date in the past and a delta has not yet been completed, the migration is incomplete and recent mail will not have been migrated. |
| Check Date Range | Investigate if missing emails precede the default start date (01/01/2000). Solution: Go further back! |
| Rule Out Deletion | Confirm items were not migrated, deleted at destination, and then remigrated (which skips items based on Migration History). The solution is to clear migration history (for affected users or the whole migration project) and rerun. |
Confirmation and Escalation
- Identify Specific Missing Emails: Obtain specific Message-IDs from the client that are confirmed missing. Google provide a guide to find the ID for different providers here.
- Confirm ID in Destination:
- Gmail: Search destination specifically using:
in:anywhere rfc822msgid:[message_id]. - Other: Search via to/from address, Subject, Date, or ID.
- Gmail: Search destination specifically using:
- Investigation: If a message in scope is confirmed missing:
- Self-Hosted: Search the latest migration trace(s) for the Message-ID. Search for "Skipping" or "has already been migrated, skipping". This indicates existing Migration History; clear history and remigrate. Review [WARN] or [ERROR] entries. If you still cannot find the answer, log a ticket with Support.
- Hosted: Log a support ticket. Only CloudM have the access required to investigate traces (DEBUG or TRACE level required).