"Security attacks are unfortunately becoming a more regular occurrence," Yahoo senior vice president for platforms and personalization products Jay Rossiter said at the time that cyber attacks were "becoming a more regular occurence."
Rival Web-based email service providers such as Google have encouraged people to use "two-factor authentication" that calls for passwords to be backed up by something else, such as codes sent to smartphones in text messages, in order to get into accounts.
Yahoo has said it hopes to phase out passwords to make email more secure, while adding improved encryption.
New Yahoo Mail software, which the California-based Internet-pioneer said marked the 18th anniversary of the free service, also let users manage Outlook, Hotmail, or AOL email from inside Yahoo accounts.
Yahoo Mail apps tailored for mobile devices powered by Apple or Android software boasted smarter search and contact management capabilities as well.
"Mobile use requires a faster and smarter inbox," said Jeff Bonforte, senior vice president of communication products at Yahoo.
"Both of these needs are at the center of our new app."
Versions of the new Yahoo Mail app began rolling out on Thursday as capabilities were added to the service accessed from desktop computers.
Yahoo chief executive Marissa Mayer has made a priority of keeping the company in tune with mobile Internet lifestyles. Making Yahoo Mail a preferred option could help put the company at the center of people's daily routines.