Oliver, another Ars Technica reader, has taken Mithras’ MailWideScreen bundle and tweaked it some more, following the advice of Malacoda.

He added alternating background colours for the rows in Message Viewer, vertical lines and small scrollbars.

He has posted screenshots of the result in the Ars Technica thread .

These tweaks are done by editing the nib files in Mail.app’s Resources Package with an app called Interface Builder, which is part of the Mac OS X Developer Tools.

These tools are not installed by default, but you can find them on your installation discs, where they live in a folder called “Xcode Tools”. After installation you will find them in a folder called “Developer” in the root directory (this may not be the right word, but a hangover from pre-Mac days) of your harddrive.

If you have them installed, you can navigate to the MessageViewerContents.nib file in your Contents/Resources/English.lproj/ folder of Mail.app’s package, click on it and it will open in Interface Builder.

At this point, I should confess that I have absolutely no idea what I am doing in Interface Builder, so if you want to read on and fool around with the way Mail looks (as I did), it’s at your own risk.

I recommend backing up Mail.app at the very least, or creating a duplicate of Mail.app and dragging it to the Desktop for safe keeping. Closing Mail first seems like a prudent step too.

It’s easy enough to create Oliver’s extra tweaks. When the nib file opens, click once on the Column view of the main window to select it:

Then bring up the Inspector, pictured above on the left, by pressing Shift-Command-I or Window > Show Inspector. All the options are there. Save your changes, quit and you’re done.

But once you start, it’s hard to stop. There’s lots more MailWideScreen-independent fun to be had. You can slim down the scrollbars whether you use the hack or not:

Or you can give the message viewer a once-over all your own. Here it is with alternating colours and horizontal lines:

I decided to stop before I busted something. But you don’t have to.

UPDATE: The MailWideScreen plugin has a new name: Letterbox Apple GUI, mail.app, apple mail, hacks, widescreen, bundles, nib, interface builder, mods

Bryan Veloso takes Hawk Wings’ little posts on replacing icons in Mail.app’s interface and on the “Hasta La Vista” Windows replacement set to a whole new level.

He has posted an excellent tutorial with screenshots on replacing the icons in the Mailbox Drawer.

He uses Pixadex and icons from the Minium icon set , but you could use any icons that took your fancy.interface, mail.app, apple mail, icons, hacks, mods

So, you’ve replaced Mail’s Dock icon and got some shiny matching new mail badges, but you are still thirsting for more Apple Mail interface customization?

VK4DX shows you how to replace the inbox icons in Mail.app with the icons from Thunderbird, so that your Mailbox Drawer will look like this:

Wanting to make Thunderbird look like Apple Mail I can understand. This one, I’m still thinking about.

Of course, the real value of this tip is that it shows you how to replace tiff files inside Mail.app’s Resources folder.

Using this method, you are not restricted to changing the icons to Thunderbird ones. You can use any image you want:

icons, hacks, interface, mail.app, apple mail, mods, mailboxes