David F. Bills posted a tutorial for adding custom CSS signatures to your iPhone email defaults. You actually have to encode the image directly so it arrives with your message. Otherwise, spam blockers may block the image download if you just use an HTML link. This tutorial will work on all versions of the iPhone. Including the iPhone 3GS, 3G, and 2G.
SSH into the phone and copy this file to your computer:
/private/var/root/Library/Preferences/com.apple.mobilemail.plist (1.1.3 and below)
/private/var/mobile/Library/Preferences/com.apple.mobilemail.plist (1.1.4 and above)
You will need to edit the SignatureKey value. If this value is not present, go into iPhone’s Settings: Mail: Signature and change it to anything other than the default. This should create the key value.
Now lets design-
Here is my code:
<div style=”font: 10px ‘Lucida Grande’, Verdana, Arial, Sans-Serif; line-height: 18px; color: #525252 ; margin: 6px 0; padding: 6px; border-top: 1px #999999 solid; border-bottom: 1px #999999 solid; background: #fff”>
<div style=”padding: 8px 0 2px 70px; background: url(‘paste your code from DataURLMaker(link below) starting with data:image/jpeg;base64, and ending before the quotation‘) no-repeat 0 1px ;”><strong>Michael Wittchow</strong><br><a href=”http://limitededitioniphone.com”>LimitedEditioniPhone.com</a><br>
Sent via iPhone 3GS</div></div>
Since it has become commonplace for email clients to deny http downloads in the body of emails, you should encode the jpeg image directly into base64 using DataURLMaker.
Now paste the your code into the SignatureKey string field, save, upload, CHMOD 777, reboot the iPhone, and bring up a new mail message on the iPhone. You should now be able to see your custom css signature. Please make sure you keep your picture size low, It will not work if your image is too large.[youtube:http://www.youtube.com/watch?v=-KeNAM92GEQ 425 350]
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