Snow Leopard is full of little surprises.

Last night, I posted an icon of Canada’s first ever mail stamp as a mail.app icon, and simply assumed that the tried and true way of changing it through the Inspectors still works. It doesn’t.

As Chocky helpfully points out in the comments (thanks!), the permissions of the core apps in Snow Leopard have been tightened so that you can’t by default copy and paste over the image of the icon in Apple Mail’s Inspector pane anymore.

However, all is not lost. I first tried brute force. I copied over the icon in Mail’s application package. That works fine, but is a little involved.

Fortunately, a few, simple additional steps can make the old method work again.

First, close Mail. Find Mail in the Applications folder, and press ⌘-I (Command + i) to bring up the Inspector pane.

Step One: Unlock it by clicking on the padlock in the bottom righthand corner of the pane. You will need to authenticate.

Step Two: Change the permissions listed for “everyone” from “Read only” “to Read & write”.

Step Three: Proceed as normal under the old method. Copy (⌘-C) the image of the icon that you want to use from the top lefthand corner of its Inspector, Select the Mail icon in its Inspector and paste (⌘-V) the new image over.

Step Four: Remember to change the permissions back to what they were.

All done! I’ve tried this three times now, and it’s worked every time. At the end of the process you have the new hand-crafted icon on Snow Leopard’s Mail:

If, on second thoughts, the new icon looks terrible, it’s easy to change it back again. Apple Mail, hacks, mail.app, icons, stamp icon, snow leopard, permissions

Kuswanto at Zeusbox has written a snappy little tutorial on how to hack iCal’s icon so that its colour matches your theme or replacement icon set but still updates with the right date every day.

It involves digging around inside iCal’s application package, extracting the right icon and either modifying it yourself or using someone else’s. Kuswanto is using the blank iCal icon from the Ekisho system icons replacement set .

The creator of the Ekisho set has also created a set of Mail.app stamp icons:

They come tilted and straight, with and without the postmark. You can download them all in a zip file from the designer’s web site.ical, icon, hack, mail.app, apple mail, stamp icon, icons

The utility that I use to wrangle many of the icons on the Alternative Mail Stamp Icons List has just been updated.

img2icns is a freeware, open-source application that converts image files (supporting every format that I have ever thrown at it) into mac-friendly icons.

Its redesigned interface offers you a choice of output formats – icns file or a folder with an attached icon – and an export path.

Conversion is as easy as dropping the image(s) onto the interface’s bulls-eye:

It’s a very handy tool to have in the cupboard. Better yet, it doesn’t cost anything.

The app is freeware and available from the developer’s web site .images, icons, convert, freeware, mail.app, stamp icon