It depends on what you mean by "email preferences." If you mean "use a new email address", then follow the steps in group 1 below, and then group 2. If it's "change the settings for a particular group using an email address that Yahoo already knows", then jump straight to group 2.
Log in to your YahooGroups account. Go to the YahooGroups page. https://groups.yahoo.com/neo
If you haven't logged in to Yahoo recently, it will ask you for your Yahoo ID and password.
Once you are logged in, use the Settings icon in the upper right (looks like a gear) to access "Account Info"
Then select "Account Security" from the menu. You'll probably have to re-enter your password.
Use the Email Accounts menu pick to add/delete addresses. You'll have to verify a new address (I think by entering a code sent to that address) when you add it.
(Note: I think this is how it works. I actually don't have an "add new email address" option, I think because I already have four verified addresses.)
Go to the 070 YahooGroups home page. https://groups.yahoo.com/neo/groups/070/info
You may have to enter your Yahoo login info to get there.
Click on the "Membership" link in the upper right, and select "Edit Membership"
Edit each of the sections by clicking on the pencil icon by each.
Change the email address for message delivery within the Identity section. (You can only select email addresses that are already in your Yahoo account.)
Change your delivery choice (individual messages, daily digest, specials only, or no messages) within the Subscription section.
From: Charles Odom ki4vmk@...  <070@...>
To: PODXS <070@...>
Sent: Fri, Dec 1, 2017 7:01 pm
Subject:  E-mail question
How do I go about changing my email preferences on Yahoo Groups.
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