Why can't I Send An Email From My Galaxy J3V?

[MASSIJC]

I'm using yahoo email perfectly well on my S5 and my daughter's S7 but my wife's J3V will only receive emails and not send them. The error is : Unable to send email

Error occurred on email server. -

530 5.7.1 Authentication required

Please help

[MASSIJC · Accepted solution]

I solved it myself. The telephone number of the device I was using was not listed in the yahoo settings. Once I added and authenticated the device phone number......authentication solved and emails sent.