If I understand your scenario correctly, you have a FOCUS for z/OS process running. From within the process, you'd like to send out emails via XMITIP.
When I worked in FOCUS for z/OS we had several apps that sent out emails (messages and small reports) via XMITIP.
We basically had a two-step process:
1. Dynamically create JCL batch job that sends email.
2. Dynamically submit the job.
Pseudocode..
-WRITE MYJCL //JOB1 JOB ..
-WRITE MYJCL //STEP1 EXEC PGM=IKJEFT1B ..
-WRITE MYJCL //SYSEXEC DD ..
..
DYNAM SUBMIT MYJCL
It was pretty powerful stuff, that had an extremely high success rate.
(Kudos to Lionel B. Dyck, and the other folks who put XMITIP together.)