If you’ve already tried ENDMSF then STRMSF, are you also setup in WRKDIRE on the HA box?
Use DSPDSTSRV to verify your DSTQ and Routing Table.
If everything appears correct, check the Dist Log (DSPDSTLOG) and review the details for the 3 jobs QZRCSRVS, QMSF, and QDIA. There should be some info in one of the 3 joblogs.
Did your source IP address change? Maybe your mail relay server was configured to permit only relay from the old system IP address.
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