Introduction
Got a PST full of Outlook email you need in Gmail? The frustrating part isn't the migration itself — it's discovering that Gmail doesn't read PST files at all, and the paths that seem obvious are more limited than you'd expect.
This guide cuts through that. Which methods actually work, where each one falls short, and how to run a clean migration with folder structure, contacts, and attachments all included.
Gmail doesn't read PST files. That's the core problem. Everything in your Outlook archive — the emails, the contacts, the calendar entries, the folder structure you spent years building — is locked inside a format Gmail has never heard of.
The way around this comes down to three options. Google makes its own migration tool. There's a manual method using Outlook and IMAP. And there are dedicated PST converters that read the file directly and push it into Gmail. Each one has different constraints. Whether you're on a personal @gmail.com or a paid Workspace account matters. How big your archive is matters. What you need beyond email matters.
Here's how each path actually works — and how to run whichever one fits you.
Three Ways to Move PST to Gmail (and Where Each One Falls Short)
Before picking anything, it helps to know what you're walking into.
Google Workspace Migration for Microsoft Outlook (GWMMO)
sounds like the obvious first choice — it's Google's own tool, built specifically for this. Download it, authenticate, point it at the PST, and it pushes directly into Gmail. Clean process, at least on paper. But two things bite people consistently. It only works with Google Workspace paid accounts — if you're on a personal @gmail.com, you're out before you even start. And it has a silent 25MB attachment limit. Not a warning. Not an error while it's running. You find out afterward when items show up as "Failed" in the migration report. For an archive with years of email, that's a real problem.
The IMAP method works by adding your Gmail account directly into Outlook, then dragging PST folders over to the Gmail side. No extra tools, no install — just Outlook panels side by side. For a small archive with mostly email and no particular attachment concerns, it's genuinely fine. The problems start with anything larger. IMAP sync stalls. Messages duplicate. Items drop without saying anything. Folder structure often doesn't survive the move — deeply nested folders tend to flatten or get cut off. Contacts and calendar don't follow at all; that's just not what IMAP does.
Which brings you to a dedicated converter. These tools read the PST file directly without going through Outlook, handle personal Gmail and Workspace accounts equally, and migrate folder structure, attachments, and email without the 25MB ceiling. Contacts and calendar need separate export passes, but they're supported. The rest of this guide walks through that approach.
GWMMO only works with Google Workspace accounts, not personal @gmail.com addresses. If you're migrating to a personal Gmail account, use a dedicated converter or the IMAP method instead.
What to Expect (and What Won't Follow Automatically)
The email side is usually fine. Headers, body, timestamps, inline images, attachments — they come over. Your Outlook folders become Gmail labels, which looks different in the interface but works the way you'd expect.
Where people get caught is assuming that's everything.
Contacts don't follow the email migration. Neither does your calendar. They need completely separate export passes — CSV or vCard for contacts into Google Contacts, ICS for calendar into Google Calendar. I've watched people finish a migration, declare it done, and then spend an hour wondering where their address book went. Plan for these before you start, not after.
Attachments have a split depending on which path you use. GWMMO silently drops anything over 25MB and those items show as "Failed" in the report — no warning while it runs. Dedicated converters don't have that cap, though Gmail itself limits message size during delivery. Worth checking your largest attachments once the migration finishes.
As for tasks and notes — they largely don't have a clean landing spot in Gmail's structure. Export them separately before starting if you actually need them. Trying to retrieve that data afterward is painful and usually not worth it.
How to Move PST to Gmail (Step-by-Step)
I've run more of these migrations than I'd like to count. The tool I use is MailExel — not because it was the first thing I tried, but because it was what I landed on after a couple of others stalled on larger archives. It reads PST directly without needing Outlook open, and it migrates straight into Gmail with folder hierarchy intact. The steps below follow that workflow.
One thing before anything else: check Gmail storage. I mean actually check it, not just assume it's fine. I had a migration once — not a small one — that stopped cold at about 60% with no error message, no indication of what went wrong. Just... stopped. I spent probably forty minutes working backward through logs before I thought to look at the destination account's storage. Full. Not close to full — full. A half-uploaded archive is a real mess to deal with. If your account is anywhere near its limit, clear space or upgrade first.
To follow these steps, you'll need the software installed. Download it below — takes about a minute, then come back and start at Step 1.
Launch the application and use Add Files to select your PST — or Add Folder if you're working with multiple PSTs from different accounts. Everything loads as one job. Files appear in the main panel ready for scanning.
Once loaded, the software scans everything automatically: emails, contacts, calendars, notes, tasks. Nothing to do here. Most archives finish in a few minutes; larger ones take longer proportionally.
The preview shows your full folder structure with item counts. Look at this before you run anything.
I skipped this once on an archive I was sure was simple — turned out there was a shared mailbox folder in there from a decommissioned account, sitting quietly with several thousand emails. Would have imported the whole thing into the wrong destination. Check the preview. It takes two minutes and catches the things you didn't know to look for. For Gmail specifically, watch for deeply nested folders with long names — Gmail labels have character limits, and special characters in folder names can cause problems.
Choose Gmail or Google Workspace as the output destination. You'll sign in with your Google account and grant the required permissions. For Workspace accounts, confirm that migration permissions are enabled — your admin may need to turn that on.
If you only need a specific date range — migrating one project period's worth of email, for example — configure that filter here before running.
Start the export. The tool connects to Gmail and pushes emails folder by folder, converting your PST folder structure into Gmail labels as it goes. When it finishes, open Gmail and spot-check a few labels — body content, headers, and attachments all intact. At least one folder that had large attachments.
Contacts and Calendar: The Rest of the Move
Email is done. The rest takes two separate passes.
For contacts, run a second export in the converter targeting contacts only, with CSV or vCard as the format. Open Google Contacts at contacts.google.com, go to Import, and upload the file. They sync to Gmail automatically from there.
For calendar, export calendar items from the PST as ICS. In Google Calendar: Settings (gear icon) → Settings → Import & Export → Import, then upload the file. Events land in "Other calendars" by default — move them to your primary calendar from there if you want them integrated.
One thing worth knowing about recurring events: complex recurrence patterns sometimes don't transfer cleanly. After the ICS import, spot-check a few repeating events to make sure the recurrence rules came through correctly before you rely on them.
Common Problems and How to Fix Them
Most PST to Gmail migrations hit at least one snag. Here's what usually causes them.
Migration stops midway with no clear error.
Check Gmail storage first — that's the cause more often than you'd think. If storage is fine, it's likely a connection timeout on a large batch; restart, and most dedicated converters resume from where they left off rather than starting over.
Everything landed in one folder — no structure.
The tool either didn't preserve hierarchy or you used the IMAP method. With a converter, check the folder/label settings before running. Go to Settings → Labels in Gmail to see what actually came through.
Attachments missing from some emails.
If you used GWMMO, anything over 25MB was silently dropped — those items show as "Failed" in the migration report. Re-migrate them through a dedicated converter. If you used a converter and attachments are still missing, check whether attachment export was enabled; some tools have it off by default.
Duplicate emails.
Classic IMAP issue — the sync ran the same folder twice. Delete the duplicates. Before restarting an IMAP connection, always check what's already been synced; dedicated converters track what's been pushed and won't re-push it.
Contacts or calendar are nowhere.
They need their own export passes — they don't come along with email automatically. CSV or vCard for contacts into Google Contacts, ICS for calendar into Google Calendar. If you're missing them, run those export passes now.
Converter won't open the PST.
Two likely causes: Outlook is still running and has the file locked (close it first), or there's corruption. Run ScanPST.exe — search "Inbox Repair Tool" in Windows — to check and repair. If ScanPST can't fix it, try the converter's recovery mode; dedicated converters often get content out of PSTs that Outlook itself won't touch.
- Check Gmail storage before starting — make sure you have enough room for the full PST.
- Work from a copy of the PST, not the live file.
- Close Outlook before running any migration — it locks the PST when open.
- Run ScanPST.exe on any PST from a machine that crashed or shut down improperly.
- Verify the preview panel before running — confirm folder scope and item counts.
- Plan separate export passes for contacts (CSV/vCard) and calendar (ICS).
- Spot-check emails, attachments, and Gmail labels after migration completes.
- Keep the original PST until you've confirmed everything landed correctly in Gmail.
Frequently Asked Questions
Can I import a PST file directly into Gmail?
No. Gmail doesn't support PST files natively — there's no direct import path. You need either Google's migration tool (Workspace accounts only), the manual IMAP method via Outlook, or a dedicated PST to Gmail converter.
Does GWMMO work with a personal Gmail account?
No, GWMMO is for Google Workspace paid accounts only. Personal @gmail.com accounts aren't supported. Use a dedicated converter or the IMAP method instead.
Will my Outlook folder structure come through in Gmail?
Outlook folders become Gmail labels. With a dedicated converter, the folder hierarchy typically carries over as nested labels. The IMAP method often flattens it or loses deeply nested structure. Very long folder names or names with special characters can get cut off — check Gmail Settings → Labels after the migration to see what actually came through.
What happens to contacts and calendar during PST to Gmail migration?
They don't come with the email migration automatically. Contacts need a separate export as CSV or vCard, then imported into Google Contacts. Calendar events need a separate ICS export, then imported into Google Calendar. If your PST has all three, plan for two separate passes after email.
What's the attachment size limit for PST to Gmail migration?
GWMMO silently skips attachments over 25MB — they show as "Failed" in the migration report. Dedicated converters don't have that cap, though Gmail has its own limits on message size during delivery. For very large attachments, uploading to Google Drive and linking from the email is often the cleaner option.
Wrapping Up
Which path you take depends on your account type and what you're moving. GWMMO is fine if you're on Workspace and your attachments are under 25MB. IMAP works for small archives where folder structure doesn't matter. For anything beyond that — personal Gmail, a bigger archive, contacts and calendar to bring over, or no Outlook available — a dedicated converter is the practical choice.
Check Gmail storage before you start. Look at the preview panel before running. Do contacts and calendar as separate passes after email. Spot-check a few things in Gmail when it's done.
Running into something specific? Drop it in the comments.
