[exim] event_action on deferral

Hi,

I am using event_action on the smtp transport to try and track deliveries, bounce and deferrals to a database. My issue is that I receive the following in the log when debugging

11:02:43 5102 LOG: MAIN
11:02:43 5102 == xxxx@??? R=dnslookup T=remote_smtp defer (-45) H=mta5.am0.yahoodns.net [x]: SMTP error from remote mail server after MAIL FROM:<x> SIZE=7077: 421 4.7.0 [TSS04] Messages from xxx temporarily deferred due to user complaints - 4.16.55.1; see https://help.yahoo.com/kb/postmaster/SLN3434.html

Which doesn’t appear to raise the defer event_action,    event_action works on deliveries and other deferrals such as timeouts.  

Can someone help me with some insight into this?

--
Paul