Hi, first of all let's to provide context. I colaborate with a selling company that has asked me if it's possible to add to their signatures the best offer they have each week. It seems easy, but the challenge is that they don't want to be editing the signatures of all their accounts. Instead, they just want to edit the offer in one place and let the signatures get that info. Finally, they've also asked me that the offer be a link to a website with more info about it. The first solution I thought was to make a resource that could be requested by Javascript using an XMLHttpRequest object that returns a string with the offer info and then just show it as I want. I discovered quickly that the signature doesn't execute Javascript code. The second solution I tryed was to make a simple web that shows just a string with the info and embed it using an <iframe>. I got it, it was the solution, but unfortunately there are mail servers like gmail that doesn't allow <iframe> tags in their mails. So this solutión is no more a valid option. As a third option, although much more complex, I thought to make an extension, but given to my unexperience with Thunderbird extensions, the complexity of this solution to approach such a simple task and the fact that after take a look at the Thunderbird extensions API I didn't found the way to edit the signature programmatically, I've put this solution aside for the moment. At this point (and having in mind that the third alternative, if it's possible, should be the last option), what solution do you recommend me to approach this task? Thanks and sorry for my english!