I've mentioned this in another post relating to delayed emails but thought it worth a port of its own.
To sign in to the community you now have to use an email address and receive a "verification code" which it sends to that email address.
If you are trying to sign in to the community for help because you have a problem receiving emails, you are STUFFED!
You need the verification code, sent to your email, which you can't receive because you are experiencing a problem receiving emails!
Someone hasn't thought that through.