I noticed today that Google has made a serious change in their effort to stop spam, particularly that of phishing emails. I use a hosted application that generates emails every time a specific action occurs. But all of a sudden today there were no emails. I checked my spam folder, and there they were.

I noticed something new about these emails:

1. They had big red and yellow warning messages:
   Warning: This message may not be from whom it claims to be. Beware of following any links in it or of providing the sender with any personal information.  Learn more
2. They are getting marked as spam because the 'from' email domain doesn't match the sender's domain. This is going to have a massive impact on web applications that send emails.
3. They can't be un-spammed. Even when I click 'not spam' on one of them, the rest keep going to the spam folder.

I'd like to know if there's a setting that can be turned off, or at least turned down in sensitivity, so that unmatched sending domains can still send emails.