Read this first — beta software disclaimer
OLM to Gmail is beta software. It has been tested carefully against large real-world archives — but every mail archive is different, and email formats from twenty years of Outlook versions contain surprises.
Back up your data. Before anything else.
- Keep your original .olm file. Forever. This tool reads it and never modifies it — but the .olm is your master copy and your only true backup until you have verified the results in Gmail yourself.
- Keep a second copy of the .olm on a different disk or cloud drive before you begin. A backup you have only one of is not a backup.
- Do not delete your Outlook profile, your .olm, or any source mailbox until you have personally verified the results in Gmail: counts that match, and every message you need present — dates, contents, attachments.
What you are agreeing to by using this
- No warranty of any kind. This software is provided "AS IS" (see the
license). Messages may fail to convert or upload; a small number of skips is
normal and is reported in
manifest.json(conversion) anderrors.jsonl(upload). - You are responsible for your data. The author accepts no liability for data loss, corruption, missed messages, quota consumption, account lockouts, or anything else arising from use of this tool. Incidental and consequential damages are excluded, and total liability is capped at what you paid for your license — which, for personal users, is nothing.
- You are operating your own Google account. Uploads consume your Gmail storage and run under API credentials you create and control. Review Google's terms for your account type.
- Verify before you rely. The tool reports what it converted, skipped, and failed. Reading that report is part of using the tool.
Not affiliated
This project is not affiliated with, endorsed by, or supported by Microsoft or Google. "Outlook" is a trademark of Microsoft Corporation. "Gmail" is a trademark of Google LLC. Names are used only to describe compatibility.