Migrate AOL Mail to Gmail: A Practical IMAP Walkthrough

AOL Mail still holds twenty years of receipts, eBay confirmations, family threads, and tax PDFs for a lot of people. The interface has aged, the spam filter has aged, and the mobile experience leaves a lot to be desired. Moving everything to Gmail is the natural next step, but it is not a one-click affair. AOL hides IMAP behind an app password, throttles connections without warning, and disconnects long sessions in the middle of large folders. Gmail, on the other hand, accepts the messages quickly but enforces label semantics that do not map one-to-one with AOL folders, especially for messages that lived in multiple AOL folders or had complex flags. This walkthrough covers the full path from a quiet AOL mailbox audit to a verified Gmail account with all your history intact, ordered by date, with read state and attachments preserved. It targets people who want the migration done properly the first time, with no surprises six months later when a colleague asks for a five-year-old invoice and you cannot find it.

What you need before you start#

The single biggest reason AOL migrations fail mid-run is a missing app password. AOL deprecated plain-password IMAP login for third-party clients several years ago. If you try to authenticate with your normal AOL password, you will see AUTHENTICATIONFAILED on the very first IMAP LOGIN command, regardless of which migration tool you use. The fix is to generate an app-specific password, a one-off random string that the tool uses instead of your login password.

You also need:

• The full AOL email address (e.g. name@aol.com, not just name).
• A Gmail account with enough free storage. Check Settings > See all settings > Accounts and Import to confirm storage headroom. If you are at 14.9 GB out of 15 GB, clean up first or upgrade to Google One.
• A network connection that will stay up for several hours. Hotel Wi-Fi will not do.
• A laptop or desktop you will not need to put to sleep mid-run. AOL handles reconnects poorly and a closed lid is the easiest way to corrupt a session.

If you manage this for someone else, get a written go-ahead before you generate the app password. It is reversible, but it is still a credential.

AOL connection settings#

These are the values to keep on hand. AOL has not changed them in years, but tools sometimes default to outdated ports.

• IMAP host: imap.aol.com
• IMAP port: 993
• IMAP security: SSL/TLS
• Username: full AOL address
• Password: app-specific password generated in Account Security
• SMTP host (if you need it): smtp.aol.com on port 465 with SSL

Gmail's IMAP side is imap.gmail.com:993 with smtp.gmail.com:465 or 587. If you are using a desktop IMAP migration client such as Mailbox Taxi you will plug both sets of values into the source and destination panes.

Steps#

1. Audit your AOL mailbox

   Sign in to AOL Mail in a browser. Look at the folder list on the left and note the size shown on the bottom of the inbox view. If the number is missing, click through a few large folders to estimate. Empty Spam and Trash unless you specifically need them. Old chain mail and twenty-year-old promotional newsletters add hours to the run for zero value. If you have AOL Mail rules, screenshot them so you can recreate the important ones as Gmail filters later.

   While you are in the AOL settings, look at Mail Forwarding. If a previous forward is in place, note it and decide whether to keep it.

2. Generate an AOL app password

   Go to login.aol.com/account/security. Sign in if prompted. Enable two-step verification if it is not already on. Once two-step is active, an "App password" or "Generate and manage app passwords" option appears. Pick that, name the entry something memorable like "Migration", and copy the 16-character string. Paste it into a text file briefly so you do not lose it. AOL only shows the password once.

   App password caveat

   The app password bypasses two-step verification for that one client. If you screenshot it or share it, treat it like a real password. Revoke it the moment the migration finishes.

3. Prepare the Gmail destination

   In Gmail, open Settings > See all settings > Forwarding and POP/IMAP and confirm IMAP access is enabled. Decide on a label prefix. Most people use AOL/ so that the imported folders sit together in the label list rather than colliding with existing labels named Travel or Work. If you decide later that you hate the prefix, Gmail's bulk label rename is fast.

   If your Google account uses two-step verification, you also need a Google app password unless your migration tool supports OAuth. For Gmail, OAuth is preferred because it survives password changes and does not show up under app passwords forever.

4. Run a 50-message dry run

   Pick the smallest folder you have, ideally one with 50 to 200 messages. Configure the migration tool to copy only that folder. Run it. Open Gmail and check:

   • Did the folder become a Gmail label with the prefix you chose?
   • Are the message dates the originals from AOL, or today's date?
   • Are read messages still marked read, and unread still unread?
   • Did attachments survive? Open one PDF and one image.
   • Are non-ASCII characters in subjects rendered correctly?

   If any of these fail, fix them now. After the dry run you have spent ten minutes; after the full run, fixing the same issue means redoing twelve hours of work.

5. Migrate everything

   Start the full sync in the evening or before you head out for the day. AOL is happiest with one or two parallel IMAP connections. More than that and you will see Too many simultaneous connections errors and a forced disconnect. Most migration tools default to a safe concurrency for you.

   Leave the machine plugged in and awake. Disable sleep on lid close if you can. Many tools resume cleanly after a disconnect, but the resume costs minutes of scanning each time, and if the network drops repeatedly the run can stretch from three hours to ten.

   A reasonable progress rate is 10 to 20 GB per twelve hours, including the folders that AOL throttles aggressively (anything over 50,000 messages).

6. Verify and cut over

   When the tool reports completion, do not declare victory yet. In Gmail, run searches for known-difficult items:

   • An email with a large PDF attachment from at least five years ago.
   • A thread with non-ASCII characters in the subject.
   • An archived order confirmation from a vendor you barely use.
   • A draft, if you had any in AOL Drafts.

   Spot-check folder counts against AOL. The numbers will not match exactly because Gmail conversation-threads, but they should be within a few percent.

   Set up AOL forwarding to your Gmail address under Options > Mail Settings > General > Forwarding. Add the AOL address to Gmail as a Send Mail As identity so replies still go out from @aol.com where appropriate. Tell the few people who matter that you have moved.

Gotchas specific to AOL#

AOL's IMAP server is unusually strict about IDLE timeouts. Long-running connections that sit quiet for more than about ten minutes get cut. A polite migration tool reissues NOOP frequently enough to keep the channel alive, but if you see the run repeatedly pausing and resuming, this is what is happening underneath.

Large folders, in particular Old Mail and any folder over about 30,000 messages, often need to be migrated in slices. AOL throws a session error if a single IMAP FETCH covers too many messages at once. Tools handle this by fetching in chunks of a few hundred. If you wrote your own script with a single bulk FETCH, you will see exactly this issue.

AOL also handles the IMAP \Deleted flag oddly. Messages that are marked deleted but not yet expunged sometimes appear and disappear during the migration. The cleanest workaround is to empty Trash on the AOL side before you start.

Finally, AOL has been known to display message counts that do not match the actual server count, particularly for large mailboxes that have not been opened in a desktop client for a while. Trust the migration tool's count over the AOL web UI.

Errors you will probably see#

• AUTHENTICATIONFAILED — wrong password, almost always because the regular AOL password is being used instead of the app password.
• Too many simultaneous connections — drop concurrency to one or two streams. AOL is sensitive here.
• BYE Connection closed after a long quiet period — IDLE timeout. Reduce the keep-alive interval.
• Message too large for destination — Gmail rejects messages over about 50 MB. These are rare in AOL but exist. The tool should log them; you can deal with them manually.
• Folder UTF-7 conversion error — usually a folder name that AOL stored with mixed encodings years ago. Rename the folder in AOL Mail to plain ASCII and retry.

Communicate the change#

Forwarding catches most stragglers, but for important contacts a short message helps. Two sentences is plenty: "I am moving my email to Gmail. From now on, please use new@gmail.com so I do not lose your messages in the forwarder." Most personal contacts will update their address books on the next reply. For business contacts, update profile pages, billing emails, and any 2FA recovery addresses pointing at the AOL account.

If you have an AOL to Office 365 or AOL to Outlook.com migration coming up later for a family member, the AOL side of the workflow is identical. Only the destination changes. The same goes for Yahoo to Gmail — Yahoo and AOL share much of the same infrastructure and the same throttling behaviour.

Recovery if something goes wrong mid-run#

If the tool crashes or the machine reboots, do not panic. IMAP migrations are append-only by nature, so a restart usually picks up where it left off. The risk is duplicates, not data loss. Most tools detect duplicates by Message-ID and skip them on the second pass. If you end up with a few duplicates in Gmail anyway, search by sender plus subject and use Gmail's bulk delete.

If the AOL app password has expired or been revoked mid-run, regenerate it, paste the new value into the tool, and resume.

If Gmail rejects a batch with a quota message, the per-day IMAP APPEND limit has been hit. Pause for an hour or two and continue. Google does not publish exact numbers, but the limit resets within a day and a single mailbox migration rarely exceeds it twice.

For a deeper view of the destination side of any IMAP move, the broader IMAP to Gmail migration guide covers Gmail-specific quirks like label nesting and the All Mail behaviour in more depth. And if you ever need to set up an app password again, the dedicated explainer covers what these credentials are and when they are required.