[otrs] Reply by Email

Hello: I'm fairly new to otrs, and I suppose this question has been asked before, but I'm not able to find an answer. What I want to do is to be able to reply to a ticket that is created by a customer from my mobile device, and have that reply forwarded to the customer. So, for example, Customer A sends an email to my otrs system. Otrs sends an auto-response, and also sends me a message saying there is a new ticket. I reply to the otrs system, and it's logged as a follow up, but the customer never sees the message. Is there any way to adjust the settings so that I can send replies to customers without having to use the web interface? Thanks, ~Scott