Earlier quoted context omitted.
Web pages don't have any expectation of durable persistence between views. If I go to Hackernews or Facebook or Google, I expect that the front page will not look the same as it did yesterday. Email does have an expectation of durable persistence; in fact I would argue that that is a critical feature of email - If you send me an email I can always return to my email inbox and if I open the email I will always see the…
What I am curious to know is what stops someone using this to get around spam filtering. Ie send something that gets through the spam filter then change it later. Also on another note I'm pretty sure google marks your emails as spam if you say things like "getting off gmail" or "switching provider". I have been sending emails to my mother for ages from my own domain (and email server), none of them have ever been mar…
Easy to test, really. Send her a new message with the same text as before, but without any URLs.