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Duplicate mail messages
If you run CSSMTP with SMTPD to test compatibility
of your mail workload, ensure that you have set TestMode to YES in
the CSSMTP configuration file. This parameter cannot be changed dynamically.
If you do not set the parameter, CSSMTP delivers mail messages that
do not contain errors, resulting in duplicate mail messages being
delivered if SMTPD also runs and delivers mail messages.
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