Google yesterday announced the availability of a new Labs application called Preview Pane which adds that missing feature to Gmail.

The Gmail layout does not change automatically after Preview Pane has been enabled. A tooltip on the inbox page guides the user to a button that adds another column or row to the window. Below is a screenshot of the vertical split mode of the new preview pane feature.

The preview pane column is added to the right of the Gmail inbox. The area is fully resizable, which is done with a click on the divider between the inbox and the preview pane.

A click on the down arrow icon next to the preview pane’s button opens a menu with options to switch from horizontal previews to vertical previews.

The selection boils down to personal preferences and the resolution of the monitor. Vertical preview mode has the look and feel of desktop email programs.

Email previews are displayed whenever an email gets selected in the inbox or another mail folder.

But the preview pane adds more than just previewing of emails in the Gmail inbox. It can also be used to quickly reply to the selected email. All controls are available right on that screen.

Gmail users can also hide the preview pane again by selecting the No Split option from the down arrow.

Preview Pane adds a feature to Gmail that has been missing since day one. While it won’t entice me to use the Gmail web interface more often, it can surely make a difference for users who work with that interface on a daily basis. (via).

Roman pointed out that he discovered Find Big Email, a free service that creates a storage report for all Gmail emails.

The service updates statistics during the scan, and an email at the end of the scan lists the top 20 biggest emails in Gmail, as well as emails that are larger than 2 Megabytes, 500 Kilobytes and 100 Kilobytes.

Find Big Email creates labels in the Gmail account that list those matching emails directly. This makes it easy as pie to delete large emails that are no longer needed. It cannot get much easier to find big emails in Gmail. The service revokes all access permissions after the scan has completed, which means that you do not have to manually do that.

The biggest concern that many users may have is that you need to authorize the service to access your Gmail account. While you do not have to enter your password to do that, it still means that the third party service can access all of your emails. If you have trade secrets in your account, other valuable or personal information, or have important accounts linked to your Gmail account, you may prefer a different solution.

One solution is to use an external email program to download all Gmail emails to a local computer to find out which emails use up the biggest amount of space on Google Mail. I recommend Thunderbird for the job but you can basically use any desktop email program, Microsoft Outlook is fine as well for instance.

Thunderbird is available for Windows, Linux and Mac. It is not as easy to use as it requires some initial configuration on your side to link the Gmail account to the desktop email client. Once that is setup though it is more or less automatic.

The account creation screen will be displayed right after installation. You need to enter the account name, email address and password. Thunderbird will handle the rest and look up the Google Mail server information automatically. Make sure you keep the IMAP mail protocol setting and do not switch to POP3.

You still need to make one configuration change though if you want that your deleted emails in Thunderbird are automatically removed from Gmail as well. Click on Tools > Account Settings.

Locate your Gmail account in the listing and select Server Settings. Now switch from When I delete a message > Move it to this folder to Remove it immediately.

The final change is to enable the size column in the email listing. Click the last icon in the email header listing of the Gmail inbox and enable the Size column.

The column displays the size of every email in that folder, including its attachment size. You can now sort by size by clicking on the Size column in the header.

Deleting messages in Thunderbird will now automatically delete those messages in Gmail as well.

While it takes longer to identify big emails in Gmail this way, it is the safer way of doing it as no one but you gets to access all the emails of the account.

Bonus tip for the impatient. You can display all emails with attachments in Gmail by searching for has:attachment. While you still cannot sort those emails by size, it is usually fair to assume that the emails with attachments take up more space than emails without. Good for some quick cleaning, especially if you can identify messages that you do not longer need to keep.

Gdow is a lightweight portable application that runs quietly in the Windows system tray. It will check the Gmail inbox sporadically and notify the user when new mails have arrived. The gmail mail notifier will display the current unread mail count of the Gmail inbox in the system tray and even display mail previews when hovering over the system tray icon.

The gmail mail notifier has to be configured before it can be used. Among the required settings are the Gmail username and password. The user can configure the type of information that are displayed (object, summary, sender’s name and address), the way it is displayed (messagebox, popup balloon, transparent form).

It is furthermore possible to change the mail check interval and enable sound notifications for new mails. The system tray icon contains a link to the Gmail inbox. The way the inbox is opened can be configured in the options as well. Among the options are the possibility to open the inbox in the default web browser or default email client.

Gdow uses roughly 12 Megabytes of computer memory while running. The Gmail mail notifier will run on most Windows operating systems including Windows XP and Windows Vista.