Adobe Security Issue

I logged on to Adobe's website to try to get a replacement copy of Adobe Photoshop Element 2018, after my computer crashed and destroyed all my applications.  When I logged in, Adobe ask me to submit a phone number for two factor authentication, which seemed like a good idea.  However, Adobe security then turned around and sent me a "Your Adobe security profile has changed" message in unencrypted email that included my phone number.  

Anyone with a little technical knowhow can capture any unencrypted data flowing over the internet.  Anyone with a little more knowledge can break into email servers and read unencrypted email.  Else why are all Adobe's pages served over HTTPS?  Why is an organization that is supposedly knowledgable about security committing such a serious security breach?