An administrator’s guide to configuring Gmail in Microsoft Outlook

Admin's guide to configuring Gmail in Outlook

Recently, I’ve seen a lot of users in corporate environments using Microsoft Outlook as their interface to Gmail. Outlook is meant to serve as a universal inbox for many different kinds of mail services, so using Gmail in Outlook with other email accounts is definitely in line with Outlook’s intended use. However, using Gmail in Outlook can be tricky, especially since there are various ways to do it.

If anyone in your user base is using a mix of Gmail and Exchange, and using Outlook as an interface to both, you should know how the two can be configured if you’re ever called in to fix anything. It’s also possible you will be asked to set up this type of arrangement for less technically-savvy users and even those high enough on the totem pole to demand it.

Table of contents:

Should you use POP or IMAP when connecting Outlook to Gmail?

Gmail lets you connect a mail client -- such as Outlook -- via one of two mechanisms: POP and/or IMAP. POP is the same legacy mail technology we’ve used for decades to fetch email messages from Internet hosts and store them locally. IMAP is the “newer” system; messages are kept on the host and the client is used to display, browse and edit the messages remotely.

Using Outlook in conjunction with Exchange is similar to how IMAP works -- and it’s possible to connect IMAP clients to Exchange servers -- but Exchange and Outlook together add a good deal more functionality than IMAP alone provides, like shared calendaring. In either case, outgoing messages that come from Outlook are delivered via SMTP.

If you’re in doubt about which protocol to use when connecting Outlook to Gmail, here are some pointers:

  • POP is useful if you plan on keeping all email local. Basically, it treats Gmail as a glorified POP recipient. Email is always downloaded locally; although you have the option to keep the downloaded messages stored in Gmail. It’s also useful when you’re using Gmail to forward email or if you’re in the process of migrating away from Gmail.
  • IMAP is better if you want to keep email stored remotely on Google’s servers. Only message copies are stored locally; headers and message bodies are downloaded on-demand when you access each folder.

If your users are accessing Outlook from a corporate machine in a fixed location and using Gmail from the Web while on the road, this is the best option. They can use either one interchangeably without affecting the other’s ability to access any particular message.

Note: You can add a forwarding address directly to Gmail, although in some environments, you may want to fetch mail directly from Gmail instead of relying on it to do the forwarding.

  • It’s also possible to enable both POP and IMAP and to use clients that access the same Gmail account via either protocol. While there are very few scenarios where this is useful, there is one I can think of.

The user could have a copy of Outlook on a desktop and another in a notebook, with the former set for POP access (in order to store everything locally) and the latter set for IMAP (so that mail received on-the-go can be examined non-destructively).

That said, I recommend picking one protocol for Outlook and sticking with it, using Gmail’s Web interface for on-the-go use and strongly discourage mixing the two if you’re ever asked to do so.

Enabling Gmail for POP3 or IMAP clients

Gmail doesn’t accept email from POP3 or IMAP clients by default. This is a security measure that keeps hackers from sneakily connecting to a user’s account and siphoning off email when you’re not looking.

To set up Gmail to allow either kind of connection, open the Gmail account and click on Mail settings. Next, select Forwarding and POP/IMAP.

Setting up POP

If you want to set up POP, select the appropriate option under POP Download:

  • Enable POP for all mail. This allows a user to connect a POP mail client to Gmail and download everything in the inbox to the Outlook client as it if were freshly delivered there. This is the best approach if you want to begin using Outlook as your POP mail client and grab everything sitting in the inbox.
  • Enable POP for mail that arrives from now on. This only allows future mail to be accessed via POP. It is handy if you want to keep existing mail in Gmail and sift through it manually, then have Outlook pick up all future mail that arrives.
  • When messages are accessed with POP. This option lets the user choose which action is taken when Outlook downloads messages via POP:
    • Keep a copy. Useful if the user is only using Outlook provisionally to access his mailbox. This way, the contents are left as-is and he can use Outlook and Gmail’s Web interface interchangeably without losing any info.
    • Mark it as read. This is the same as the previous option except that the email message is marked as “read.” This is useful if you’re accessing Gmail from both the Web and Outlook, and have so much mail that you forget what you’ve looked at and what you haven’t.
    • Archive it. This is the same as Mark it as read, except that the email is moved into Gmail’s archive when downloaded. This is a good alternative if the user doesn’t want to keep previously accessed email messages in your inbox, but still wants to access them through the Web interface.
    • Delete it entirely. This should only be set if you plan on immediately moving all the users mail into Outlook. For safety’s sake, I suggest using the Archive it option in the interim, unless you’re confident that mail is being piped into Outlook without issue.

After selecting an option, the Configure your email client link will give you detailed instructions on how to connect Outlook to Gmail. The instructions cover Outlook 2002 through Outlook 2007; Outlook 2010 is functionally the same as Outlook 2007 in this respect.

Setting up IMAP

To set up IMAP, go to the options under IMAP Access. Select Enable IMAP, then set the rest of the options:

  • When I mark a message in IMAP as deleted. This controls the auto-expunge function. When a message is marked as deleted in Gmail via IMAP. There are two options:
      • Auto-Expunge on. The deleted email is immediately moved to the trash.
      • Auto-Expunge off. The deleted email is handled one of three ways (controlled by the next option).
  • When a message is marked as deleted: This controls what happens when auto-expunge is off and a message is deleted via IMAP:
      • Archive the message. The deleted message is moved to the server-side Gmail archive for the mail account.
      • Move the message to the Trash. The deleted message is moved to the Trash folder. In Outlook, this folder is labeled Trash under the [Gmail] folder for the Gmail IMAP account (Figure 1). It is not the client-side Trash folder that is automatically created for the Outlook data file and used in conjunction with the Gmail IMAP account.
      • Immediately delete the message forever. This is exactly what it sounds like.

A look at the Gmail folder hierarch -- in an Outlook client.

Figure 1. The Gmail folder hierarchy is what is actually on the Gmail server. The highlighted Trash folder is Gmail’s own trash, not Outlook’s.

  • Folder size limits. This lets you control whether or not the IMAP folders in the user’s account have constraints on how many messages can be stored in them. Folders with a lot of messages can take a long time to update in the client.

For example, if your users access Gmail through Outlook installed on a notebook -- and using slow or flaky wireless connections -- you should set a limit to prevent Outlook from responding slowly if it polls a Gmail folder that’s filled with email. This is also a good way to prevent your own internal networks from getting bogged down by similar actions. There is no default message limit, but you can set it to 1,000, 2,000, 5,000 or 10,000

Local storage

Because Gmail gives you a few choices about how users remotely access it, you should also figure out whether to store messages locally in Outlook when connecting a user’s Gmail account. This decision depends entirely on your existing policies for local mail storage.

When you add a Gmail POP connector to Microsoft Outlook, you can choose where incoming email is delivered. If the user is using Gmail as a simple forwarder or if you’re in the process of aggregating several mail accounts down to one, you should set up Outlook to deliver Gmail’s mail directly to the main message store’s inbox.

The end user also has the option to use Outlook rules to assign a special category to such email. For example, if the user wants to give Gmail content either lower or higher priority, or if he wants to move it to a designated subfolder in a message store.

Another option is to assign Gmail its own message store. This allows for more thorough segregation and also makes it possible for users to handle Gmail stuff in a totally separate inbox. Some users like having one store per account as an organizational tactic; they deal with everything in their main inbox, then switch to the other one and handle it at their own pace.

Also, this makes it possible to reply to incoming Gmail messages from that Gmail account if they need to, instead of using an other email account set up in Outlook. If Gmail is the only account set up in Outlook, this is a moot point, but it’s still helpful to know how this behaves if you’re using other services side-by-side.

The exact reasons for enacting a “no local PST files” policy in your own organization is worth exploring.

One potential problem is if your organization has a strict no local PST files policy. If it’s a local storage management issue, the size of the PST file in question will not be a problem, since it’s just a local cache for any messages open in the current session.

You can specify which message store to use when you’re first setting up the Gmail POP account. In the Add New Account wizard, select Manually configure server settings, then choose Internet Email. Next, use the Deliver new messages to selector to choose whether to send new mail to the existing (default) message store or to a newly created Outlook message store (Figure 2).

Gmail POP accounts can deliver email to a new store or existing one.
Figure 2. Gmail POP accounts can be configured to deliver email to a new message store or an existing one.

If users access Gmail via IMAP, a local PST file is automatically created for that account. Also, messages from the remote server are synced locally so that they can be read offline. If you see an icon in the Header Status column for a given message, it means that only the header is available locally; you must open the message with a live connection to Gmail to read it.

Outlook syncs IMAP Gmail messages locally.
Figure 3. Outlook syncs IMAP Gmail messages locally. The icon to the right of the envelope indicates that a particular message is not locally synced yet.

Serdar Yegulalp
has been writing about computers and IT for more than 15 years for a variety of publications, including,, InformationWeek and Windows magazine.