How do I stop Gmail from stripping the values out of URLs?

Question

I recently learned that webmail clients like Gmail will do alterations on HTML emails, for example adding target=\"_blank\" to tags.

Answer 1

Click View original/source on the message in Gmail to see if the URLs looks like they should then. If so you know that the problem is how Gmail is formatting the message for your viewing. If it's mutilated even in the source I was wondering if there's anything in your webpage/php/CMS (do you use one) that changes the code.

You should try URL-encoding as @Crisp said. Here's the W3 reference.