Synchronization issues

Here's how to troubleshoot problems you might have with Google Apps Sync for Microsoft Outlook® while synchronizing data between Outlook and your Google Apps interface. For complete information on using Google Apps Sync, see Google Apps Sync help.

To quickly diagnose a problem, submit your trace files to our Google Apps Sync Log Analyzer. Most issues can be identified within a few moments of your submission.

See below for Mail sync or Calendar sync issues.

General Sync Issues

The Google Apps Sync icon in the Windows system tray is showing up as offline

Either your network connection is down, or Outlook might have switched into offline mode, for example, after a password reset.

I'm getting sync errors, or synchronization has stopped altogether

Did you select an Unlimited mailbox size limit in Google Apps Sync? If so your local PST file might have reached its maximum size allowed by Outlook (20GB by default), which can cause errors or prevent Google Apps Sync from syncing with Google Apps at all. You'll need to either limit the mailbox size in Google Apps Sync (see Set a local mailbox size) or follow these instructions from Microsoft to change the size limit of your PST file and store more than 20GB locally.

I'm having synchronization problems after moving folders by dragging

Reorganizing folders in Outlook via drag-and-drop can cause synchronization issues in Google Apps Sync. If you moved folders in this way and now some of your data isn't syncing, create a new profile and data should start syncing properly again.

Mail Sync Issues

My local Outlook PST file is larger than my Inbox on the Web

This can occur if a lot of your messages have multiple labels in Gmail. See above for details.

The same message appears in multiple folders in Outlook

A message that has multiple labels in Gmail appears in each corresponding folder in Outlook. It therefore looks like there are multiple copies of the message in Outlook, and the size of your local mailbox (PST file) can be larger as a result. There's only one copy of the message, however, so deleting it from one folder deletes it from the other folders, too.

Executable file attachments aren't appearing anywhere

Google Apps doesn't allow sending or receiving executable (.exe) and some other types of file attachments. Such attachments don't appear in either the Outlook or Gmail interface.


Which file types can I not send or receive?

"ade", "adp", "bat", "chm", "cmd", "com", "cpl", "dll", "exe",
"hta", "ins", "isp", "jse", "lib", "mde", "msc", "msp",
"mst", "pif", "scr", "sct", "shb", "sys", "vb", "vbe",
"vbs", "vxd", "wsc", "wsf", "wsh"

Outlook isn't showing my older messages (but the Gmail interface is)

This is probably because your local mailbox size (Outlook PST file) isn't large enough to store all your messages locally. Google Apps Sync stores the most recent messages locally (up to 1 GB by default). It stores the rest (up to 25 GB) in the cloud, where it's accessible from the Gmail interface. If you want more messages stored locally, you can increase your Mailbox Size Limit, say, to 2GB. However, this isn't normally recommended as it can have an adverse effect on performance.

I'm unable to move messages between folders in Outlook

If you're unable to move a message from one folder to another in Outlook, it could be because the destination folder doesn't have a corresponding label in Gmail. To fix the problem, try one of the following:

  • Create a label in Gmail that corresponds to the folder you're moving to.
  • Delete the folder in Outlook, and recreate it.

Note that you can't move messages directly into the Drafts folder but must save the message as a draft, instead.

I'm getting sync errors, or synchronization has stopped altogether

Did you select an Unlimited mailbox size limit in Google Apps Sync? If so your local PST file might have reached its maximum size allowed by Outlook (20GB by default), which can cause errors or prevent Google Apps Sync from syncing with Google Apps at all. You'll need to either limit the mailbox size in Google Apps Sync (see Set a local mailbox size) or follow these instructions from Microsoft to change the size limit of your PST file and store more than 20GB locally.

Sending large messages can time out over a slow connection

If you send a message with large attachments (multiple megabytes) over a slow connection, the connection can time out, leaving the message unsent in your Outbox. By default, the timeout is hard-coded to occur at 90 seconds. You can extend this period to accommodate messages that take longer than 90 seconds to send by modifying your Windows registry. Specifically, add the following keys to override the hard-coded timeout values:

  • HKEY_CURRENT_USER\Software\Google\Google Apps Sync\Other\ResolveTimeoutSeconds > DWORD Value = 00000030
  • HKEY_CURRENT_USER\Software\Google\Google Apps Sync\Other\ConnectTimeoutSeconds > DWORD Value = 00000030
  • HKEY_CURRENT_USER\Software\Google\Google Apps Sync\Other\SendTimeoutSeconds > DWORD Value = 00000600
  • HKEY_CURRENT_USER\Software\Google\Google Apps Sync\Other\ReceiveTimeoutSeconds > DWORD Value = 00000600

Note: If you're running a 32-bit version of Outlook on a 64-bit version of Windows, you'll need to add these registry keys in the correct location for 32 bit applications. For details, see the instructions on using the Windows registry at Configure limits and options via the registry.

The above values give timeout periods in seconds, and can be adjusted to accommodate your connection. For help adding these values to the registry, see below:

How do I add these keys to my Windows Registry?
  1. Open the registry: From the Windows Start menu, click Run, then type regedit in the Run dialog.

    (Or, if you're using a 32-bit version of Outlook on a 64-bit version of Windows, you should instead enter %systemroot%\syswow64\regedit in the Run dialog.)
  2. In the Registry, navigate to HKEY_CURRENT_USER\Software\Google\Google Apps Sync\.
  3. Choose Edit > New >Key. Then type Other as the name of the key, and press Enter.
  4. Select the Other folder you just created and choose Edit > New > DWORD Value. Enter ResolveTimeoutSeconds as the new value and press Enter.
  5. Right-click the new value's folder and click Modify. Then under Value Data, enter your desired timeout value (00000030,in our example).
  6. Repeat these steps to create a DWORD value for each other timeout listed above (ConnectTimeoutSeconds, SendTimeoutSeconds, and ReceiveTimeoutSeconds).

Drafts I save in Outlook don't sync to Gmail

Unfortunately, Google Apps Sync doesn't synchronize email drafts with Gmail or other computers where you use Outlook. Please finish authoring your email using the same client where you started the draft.

Sent messages aren't showing up in my Outlook Sent Items folder

With the default Outlook settings, they should. If the original settings have been modified, restore the following default:

  1. In Outlook, click Tools > Options.
  2. On the Preferences tab, under E-mail, click E-mail Options.
  3. Select the check box for Save copies of messages in Sent Items folder.

Messages I move out of my Outlook Sent Items folder later reappear there 

You can move a message out of your Sent Items folder in Outlook, also removing it from Gmail's Sent Mail label. However, that change doesn't always stick in Gmail. In Gmail, the message may later reappear in your Sent Mail label, then sync back to Outlook's Sent Items folder.

Can't view .msg or .eml file

If you attach an email message (.msg or .eml file) to a message in Outlook, recipients using Microsoft Exchange will not be able to read the attachment. To avoid this issue, it is best to forward the message itself via Outlook, rather than attach a message as an .msg or .eml file.

Calendar Sync Issues

My calendar invitations aren't syncing properly

This might be because you're receiving calendar invitations that aren't in the iCal format. Check in your Gmail interface to see if the invitation email contains a winmail.dat attachment. If it does, the sender needs to modify their Outlook settings to use iCal, as follows:

  1. In Outlook, go to Tools > Options.
  2. On the Preferences tab, click Calendar Options.
  3. Under Advanced options, check the When sending meeting requests over the Internet, use iCalendar format option.

Note that this setting might be disabled if you're using Google Apps Sync or if you're connected to an Exchange Server.

Outlook adds events to my primary calandar that belong on another calendar

If you see events on your primary calendar that you were actually invited to on another calendar, it's probably because you subscribed to receive New Event notifications for the other calendar (which you do in your Google Calendar settings). What happens is, whenever Google Calendar sends you a notification about a new event, Outlook adds the event to your primary calendar—no matter what calendar the event actually belongs to. Unfortunately, this is just the way that Outlook works with Google Calendar notifications. If this is a frequent problem, you might want to avoid enabling New Event notifications for any calendar other than your primary calendar.

Events in Outlook Calendar are showing up in the wrong time zone.

In the Google Calendar interface, verify that your time zone settings are correct. Go to Settings and set both the Current Time Zone (on the General tab), then for each additional calendar, set the calendar's individual time zone (on the Calendars tab). People who invite you to meetings must do this for their calendars, too. Learn more.

Events scheduled from now on should display in the correct time zone. For previously scheduled events to display correctly, you'll have to recreate your Google Apps profile.

All day events show up in Outlook Calendar as spanning two days.

This is probably because your time zone is not correctly set in the Google Calendar interface. Perform the steps above to specify your correct time zone. After that, delete and re-sync your Calendar data to correct any previously scheduled all-day events. To do this, right-click the Google Apps Sync icon in your Windows system tray, open the Synchronization Status dialog, and choose the Delete and re-sync option for your calendar data, only. (Note that doing this will delete Outlook-specific data from your calendar, such as colored categories you've applied to events.) For details, see re-sync or repair Outlook data.

Outlook crashes when I refresh my free/busy information

Are you using Microsoft Outlook® 2010? If so, you might need to install this free/busy hotfix from Microsoft.

I can't view other users' free/busy information in Outlook

There might be a problem with your Windows registry settings. In particular, verify that the following registry key is set exactly as shown below. If the key doesn't exist, or if its value doesn't match what's shown below, create the key and edit its value so it does.

  • Registry key: KEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\your_Outlook version\Outlook\SchedulingInformation\FreeBusySupport
  • Value name: SMTP
  • Value type: REG_SZ (string value)
  • Value data: {0006F049-0000-0000-C000-000000000046}
How do I modify this key in my Windows Registry?
  1. Open the registry: From the Windows Start menu, click Run, then type regedit in the Run dialog.

    (Or, if you're using a 32-bit version of Outlook on a 64-bit version of Windows, you should instead enter %systemroot%\syswow64\regedit in the Run dialog.)
  2. In the Registry, navigate to KEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\your_Outlook_version\Outlook\SchedulingInformation\

    where your_Outlook_version is:
    • 11.0 (for Outlook 2003)
    • 12.0 (for Outlook 2007)
    • 14.0 (for Outlook 2010)
  3. If a FreeBusySupport folder doesn't exist in this location, choose Edit > New > Key. Then type FreeBusySupport as the name of the key, and press Enter.
  4. Select the FreeBusySupport folder and choose Edit > New > String Value. Enter SMTP as the new value and press Enter.
  5. Right-click the new value's folder and click Modify. Then under Value Data, enter {0006F049-0000-0000-C000-000000000046}.

Some of my calendar, contact, notes, or tasks folders aren't syncing

Are they stored somewhere under your top-level Calendar, ContactsNotes, or Tasks folder in Outlook? If not, they won't sync with Google Apps. When creating new folders in Outlook, be sure to create them under the appropriate Outlook app (Calendar, Contacts, and so on), or their contents won't sync with Google Apps. 

In addition, create all notes in your top-level Notes folder in Outlook. Notes placed elsewhere, such is in subfolders, will not sync with Google Docs, Sheets, and Slides.

I'm receiving conflict errors when synchronizing my contacts. Is data not synching? Am I losing contact information?

If you update a contact from both Outlook and Google Apps or a separate mobile device, a conflict can occur where Google Apps Sync retains two versions of the contact. You don't lose any data when this happens—both versions of the contact are retained, and you can choose which version to keep:

  1. See which contact has conflicting versions by opening your Sync Issues folder (in Outlook Mail, choose Go > Folder List). Note that other issues might be reported here, too.
  2. Open the contact in Outlook. Outlook displays a message saying there has been a conflict, and lets you choose which version to keep.

Other Sync Issues

I'm having other synchronization problems

First, verify that your version of Windows or Outlook meets all these system requirements (install updates as necessary). Also make sure you're using the latest release of Google Apps Sync with the latest hot fixes. Learn more about getting the latest release.

Next, make sure your Outlook .PST file isn't corrupt by running Microsoft's Inbox Repair tool (aka, scanpst utility).

Are there other known synchronization issues?

There might be. See known Issues and look under Email Clients and Mobile Devices.