Hi Shawno,
Junos software on EX3300 supports routed vlan functionality, wherein a vlan can provide both bridging and routing functionality. To configure routing functionality for a vlan, follow the below steps.
1. Configure the vlan with vlan name/vlan-id
2. Configure the vlan as l3 interface for layer 3 functionality
3. Assign ip address for the vlan l3 interface
4. Allow the vlan on physical ports which needs connectivity to the vlan.
Add following configuration for your existing configuration on EX3300
set vlans Mail l3-interface vlan.25
set interfaces vlan.25 family inet address xxx.xxx.xxx.xxx/xx
Please refer following documentation.
https://kb.juniper.net/InfoCenter/index?page=content&id=KB10972&cat=SWITCH_PRODUCTS&actp=LIST