@websavers
Regardless of these values, Spamassassin is there for a reason: greylisting and DNSBLs are not 100% effective. All of this processing really should occur *prior* to any auto reply being sent, including spamassassin checks.
True, but the pivotal question here (which was implicitly defined by you) was "is there an issue in the chronological order of mail processing", with that issue leading to a very undesirable result: auto-replying to spam.
My question was dealing with the topic whether the observed behavior (of "auto-replies") is consistent across specific settings, with tests using those settings allowing us to a conclusion with a high degree of certainty that something does go wrong in the chronological order of mail processing: after all, the before mentioned settings should result in the absence of auto-replies and if that is not the case, then it can be safely established that mail processing is a bit botched.
In short, we still do not know for certain that the potential bug in the chronological order of mail processing can be confirmed.
By the way, I would normally do some testing on my side, in order to identify and/or confirm the potential bug........but the problem is that I do not have the spam or the settings that trigger an auto-reply on receiving spam.
Note that I use a pretty standard setup for any test on my side, so the absence of spam could also suggest that your config is a bit "non-default" somehow: this statement
We do not use greylisting as clients very much dislike the 1 hour delay in receiving first-time messages.
is not proving the before mentioned suggestion, but it certainly is an indication that something is different: grey-listing will not commonly result in delays of 1 hour or more, this due to the fact that (external) properly configured mail servers are retrying after a couple of minutes (for instance, 10 minutes) and increasing the interval between retries, if the next (second, third and so on) attempts are not succesful.
In general, I would recommend you to share some relevant output from /var/log/mail.log, so we can have a better idea of what is happening on your machine(s).
Regards........