Spam email from own phone

[sharki]

I am receiving some spam email since a while, nothing unusual. 

They all follow the same pattern. Usually I receive an 'invoice' I need to look at with a zip file attached. (see photo)

Today, however, I received such an email from my own email address

Could it be that some app is sending this email from my phone? I do have a Xperia smartphone.

 

I can change my password, but if my phone is causing it that won't help.

[noisebomb44]

I believe they can fake the mail adress without having acces to that account

[sharki]

It is not shown under sent items, both on my phone or online.

The email is not just sent as an alias with my name, it's really my email address.

 

This is shown as the originating IP: 117.241.36.229

Does that mean the email is not sent from my phone, but the text is just added? 
Then it still should show up in my normal sent items, right?