1) Due to Yahoo's new anti-spoofing policy, if someone uses the contact form on your site, they cannot contact you from yahoo addresses. You get a DMARC error. (I read somewhere that the solution may be something like rewriting the from address in the contact form?) Better explained here.
You can also see other articles here and here
2) When a forgot password email is sent to yahoo and live/hotmail/outlook addresses, the reset hyperlink does not show up. User will need to copy paste a long web address because it is not clickable. (Works fine in gmail)
