I have been using yahoo mail for quite some time. However, I am not really impressed with their product or their improvements. Since 2013 I had issues regarding hacking, their advertisement placement is very frustrating, their platform is very slow and these factors are some to name a few. An alternative email platform that I would recommend and I am currently using is Milfence which offers an secure email service offering end to end encryption and a protected platform.
Gmail - Gmail is available across all your devices Android, iOS, and desktop devices. Sort, collaborate or call a friend without leaving your inbox.
Thexyz - Secure premium email service with mobile sync apps for calendar, contacts, tasks, notes and FISMA compliant email archiving.
Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
ZixArchive - ZixArchive is a cloud-based solution to collect, store and search archived emails.
Zoho Mail - Zoho Mail is a secure, encrypted, and enterprise-ready email solution, a suite of apps tailor-made for your organization's needs.
Cryoserver - Cryoserver is an all-in-one email archiving solution that empowers you to preserve your email in a tamper-evident archive, making you transform your data into a useful archive for everyday use.