accessing mail from another device on network?

kind of off topic, more of a general unix/networking questions..

i have a rasp pi on my network that i use for a sshd and vpn server. i need to be able to send periodic emails.. instead of installing mail i was wondering if there was a way to make it use unraid's mail service instead since i already have it installed and set up there on the same network? or is this not possible.