Manual method
- Use a supported desktop Outlook version; this walkthrough is for classic Outlook on Windows. Confirm all needed folders and older messages have finished downloading.
- Choose File, Open & Export, Import/Export, then export to a file.
- Choose Outlook Data File (.pst), select the account or folders and include subfolders where offered.
- Save outside the live mail store and wait for completion. Open the PST in Outlook and sample old/new messages and attachments.
What you get: A PST contains the selected locally available data, not necessarily every server archive or shared mailbox. Work accounts may restrict export. A small local cache can omit older mail, so compare date coverage before proceeding. Other Outlook versions have different export controls. Provider instructions.
Size and waiting time
Planning example: 10 GB; light/heavy scenarios: 0.5–100 GB. These are estimates, not a measured population average or fixed limits. Around 50,000 messages averaging 200 KB with attachments. Corporate archives and shared mailboxes can be far larger.
Preparation: Local export may take minutes to hours; initial synchronization can take much longer. No universal provider preparation queue applies to this desktop route.
Network transfer of 10 GB: about 3.2 hours at 10 Mbps, 38 min at 50 Mbps, or 19 min at 100 Mbps. This assumes 70% sustained throughput and excludes preparation, manual work and extraction. For local exports, this is a comparison for transferring the saved files online; disk speed determines local copy time. Online backups use your upload speed. Transfer calculations and large-file examples.
Store and check your archive
An encrypted external SSD or hard drive is a good main archive for this collection. Allow roughly 30 GB of working space for the example, including an original, an extracted working copy and room to check it. Very compressed packages can need more. A USB key is useful for a spare copy, but should not be the only one. An encrypted online copy protects against losing the local devices.
Keep the original in outlook_mail/YYYY-MM-DD/original/. Record the account alias, selected scope, date range and missing items. Open old and recent records and sample attachments offline, then compare file sizes or checksums after copying. Keep the source account until you have checked the result. Storage and recovery instructions.
Sources and review
Public documentation was reviewed on 27 October 2026. No signed-in export or restoration was performed. Account options and availability can change; follow the current provider instructions.