S6 - emails come in and disappear when opened later on computer

[AC Question]

For a long time I have received Verizon email on phone. I open the email later on my home computer and it subsequently disappears from my phone. I'd like to keep them on my phone.
The incoming settings on my Samsung 6 are:
POP3 server: pop.verizon.net
Security type: SSL
port: 995
Delete email from server: When deleted from inbox

What can I change to keep the email?

thanks in advance from a non tech girl!