如何提高Fetchmail的日志级别？

从fetchmail(1) （ man 1 fetchmail ）：

增加输出的冗长度：

  -v | --verbose Verbose mode. All control messages passed between fetchmail and the mailserver are echoed to stdout. Overrides --silent. Doubling this option (-v -v) causes extra diagnostic information to be printed. 

关于debugging到syslog：

  The --syslog option (keyword: set syslog) allows you to redirect status and error messages emitted to the syslog(3) system daemon if available. Mes- sages are logged with an id of fetchmail, the facility LOG_MAIL, and priori- ties LOG_ERR, LOG_ALERT or LOG_INFO. This option is intended for logging status and error messages which indicate the status of the daemon and the results while fetching mail from the server(s). Error messages for command line options and parsing the .fetchmailrc file are still written to stderr, or to the specified log file. The --nosyslog option turns off use of sys- log(3), assuming it's turned on in the ~/.fetchmailrc file, or that the -L or --logfile <file> option was used. 

希望有所帮助！

至less在Debian中你也可以运行

 /etc/init.d/fetchmail debug-run 

fetchmail将直接login到控制台，而不是分叉到后台

将fetchmail作为守护程序运行时，增加冗余的一种方法是将“ -vv ”添加到fetchmail初始化脚本中。 例如，在Debian中，将/ -vv添加到/etc/init.d/fetchmail中的OPTIONS参数中，重新启动fetchmail，然后在/var/log/mail.log或/ var / log / syslog中查看详细输出。