In Jakarta Mail 2.0.2 it is possible to preform a SMTP Injection by utilizing the \r and \n UTF-8 characters to separate different messages.
Exploitability
AV:NAC:HAT:NPR:LUI:NVulnerable System
VC:NVI:HVA:NSubsequent System
SC:NSI:LSA:N6/CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:NOther