The Here And Now

 Yahoo email has been getting worse.Many people who are using POP or IMAP  to access their email on their phones are finding it no longer works. There is an option to "allow access from less secure apps" that may help but for many that too fails. Accessing your Yahoo email on the web is still sometimes available but often that does not work on your phone. They turned off email forwarding so you cannot forward your email to another account like gmail.

I am testing a low RAM email client (eM Client) that can run continuously in the background of my desktop. I set up an IMAP account for yahoo mail, created a filter/rule that copies the email over to the IMAP version of my gmail account and puts it into a folder so I can read it on my phone. I am certain there are other more simpler  workarounds, but the most important part of this message is to make certain you have found a way to download your Yahoo email, contacts and calendar and store it elsewhere as I am not certain how much longer yahoo will be viable.

PS.   I am am paid subscriber to yahoo mail and they no longer have a support number to call. Or rather, I am still looking for it. They have not answered any support emails and the forum gets you canned responses.

PPS. Gmail allows you to import your contacts, emails and calendar from yahoo via POP, so if you can get POP to work, that is a good way to back up your entire yahoo account. Once imported you may have problems getting new emails, but it will be a start. Also, POP only imports items stored in your mail folder (inbox. IMAP allows you to access all folders.)

PPPS. Besides eM Client, you can try other free Desktop email apps like Thunderbird for IMAP.  There may be other third party apps that work across desktops and phones.