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Migration Overview#

This documentation applies to Piler enterprise edition 2.1.0

Revision #1

Publication date: 2025-DEC-12

Overview#

Piler can import emails from any email archiving solution that exports to standard formats (EML, MBOX). This section provides step-by-step guides for migrating from popular competitors.

Supported Migration Sources#

Source Export Format Complexity Guide
MailStore EML Easy MailStore Migration
MailArchiva EML, MBOX Easy MailArchiva Migration
Barracuda Message Archiver ZIP (EML) Medium Barracuda Migration
Any EML/MBOX source EML, MBOX Easy Import Emails

General Migration Process#

All migrations follow the same basic workflow:

  1. Export - Extract emails from the source archive in EML or MBOX format
  2. Transfer - Move exported files to the Piler server
  3. Import - Use pilerimport to archive the emails

Import Tool#

The pilerimport tool handles all imports:

pilerimport -dir /path/to/exported/emails -tenantid <tenant> -workers 8 -progress

Key options:

  • -dir - Directory containing exported EML files (recursive)
  • -mbox - Single MBOX file to import
  • -tenantid - Target tenant ID
  • -workers - Parallel processing threads (default: 4, recommended: 8-16)
  • -progress - Show progress bar
  • -remove - Delete files after successful import

See Import Emails for complete documentation.

Before You Begin#

Storage Requirements#

Ensure the Piler server has sufficient disk space:

  • Exported data size + 20% overhead for indexes
  • Example: 500GB export needs ~600GB free space

Network Transfer#

For large archives, consider:

  • rsync - Resumable transfers, handles interruptions
  • USB/external drive - Fastest for multi-TB archives
  • Secure copy (scp) - For remote transfers

Example rsync:

rsync -avz --progress /source/export/ piler-server:/var/piler/import/

Permissions#

Ensure the import directory is readable by the piler user:

chown -R piler:piler /var/piler/import/

Post-Migration Verification#

After import completes:

  1. Check import statistics (success/failed counts)
  2. Search for recent and old emails to verify date range coverage
  3. Spot-check attachments open correctly
  4. Verify user access permissions work as expected

Need Help?#

For migration assistance, contact support.