How to sent an email automatically with Android?

My yahoo email account was hacked. But no unusual login activity? How was I hacked?

• Right when I used my android yahoo app (which I do infrequently) my yahoo email was hacked. Spam was sent to all my contacts. However there is no log of unusual log in activity in yahoo mail. In fact, there is no login activity I can see from my phone! I only see browser activity, no mobile activity. If I had a spoof app that collected username/password I would have expected a log of a login from some place I did not know... But I do not see this. I only see IP addresses from my home and work. How did the hack happen if they did not log into my account? The spam is in my sent folder, so I know the spam was sent from my account. But how did the hacker send email from my account without leaving a login? The only way I can think this happened is if they hijacked my email session. But how does this occur? Thanks in advance for any answers! I am mystified.

• Answer:

  I have had almost the same experience. I do have an android phone, I do not use the yahoo mail app on it. Same thing, no unusual logins.