And to clarify, some Yahoo Groups require a Yahoo account to participate. You cannot participate with a regular email address, you must sign up to a Yahoo accou

And to clarify, some Yahoo Groups require a Yahoo account to participate. You cannot participate with a regular email address, you must sign up to a Yahoo account. If you join a real-world social gathering which happens to use such a Yahoo group, you may find yourself excluded from online communication with that social network unless you agree to sign up to Yahoo.