Monitoring Mail Services

Mac OS X Server provides a variety of statistics for monitoring the Postfix and Cyrus mail services. Using the Server Admin tool, you can monitor individual mail connections, accounts, and Mail service log files. The information provided by the monitoring tools is invaluable for troubleshooting connection problems and determining if resources are being properly used.

To monitor Mail services:

1.	Launch the Server Admin tool located in /Applications/Server, and authenticate as the administrator (Figure 8.63). Figure 8.63. Launch the Server Admin tool, and authenticate.
2.	Select the Mail service for your server in the Computers & Services list. Click the Connections button to view the current mail client connections (Figure 8.64). In this frame, you can monitor client host addresses, connection types, number of sessions, and connection length. Figure 8.64. You can monitor current Mail service connections in Server Admin.
3.	Click the Accounts button to view users' mail account status. In this frame, you can monitor user mailbox storage settings and quotas (Figure 8.65). Figure 8.65. You can monitor mail account status in Server Admin.

Tips

• If you've recently enabled your mail server, you'll have to wait until clients begin using the server before any data will appear.

• Click the Refresh button to force the Server Admin tool to refresh the monitored data.

Configuring mail logs

Although the Connections and Accounts charts in Server Admin are convenient, the real business of Mail service monitoring is in the log files. The Postfix and Cyrus mail servers can provide a great deal of information in their log files. You can even modify the log file level to meet your specific needs.

Each protocol has its own log, and the Mailman list service keeps several logs. The location of each log file varies based on the service: the SMTP log file is /var/log/mail.log, the POP and IMAP log file is /var/log/mailaccess.log, and mailing-list logs are located in the /var/mailman/logs/ directory. See the sidebar "Mail Log Analysis Tools" for more information about interpreting Postfix access logs.

To configure mail logs:

1.	Launch the Server Admin tool located in /Applications/Server, and authenticate as the administrator (Figure 8.66). Figure 8.66. Launch the Server Admin tool, and authenticate.
2.	Select the Mail service for your server in the Computers & Services list. Click the Settings button and then the Logging tab to view the current mail client connections (Figure 8.67). The Logging frame shows settings for both the SMTP and IMAP/POP service logs. Figure 8.67. The Mail service is selected in the Computers & Services list, and the Settings button and Logging tab are shown.
3.	To adjust the log's level of detail, select one of the following values from either pop-up menu (Figure 8.68): Low Logs only major service errors Medium Logs all of the Low log's items plus mail messages High Logs all of the Medium log's items plus any other message or service item Figure 8.68. Configure log detail levels from the Logging Mail service settings.
4.	On extremely busy servers, the log files can become large; you may need to archive them to save space. To do so, select the Archive log check box, and enter the number of days between log rotations (Figure 8.69). Figure 8.69. The Mail logs can be archived at set intervals.
5.	When you've finished making changes, click the Save button .
6.	To view the logs, click the Logs button .
7.	Select the log file you wish to view from the pop-up menu at the bottom of the log window (Figure 8.70). Figure 8.70. A variety of mail logs can be viewed from Server Admin using the Logs button.

Tips

• You should always stop the Mail service prior to making changes and restart it only after saving your changes.

• Click the Refresh button to force the Server Admin tool to refresh the logs immediately.

Mail Log Analysis Tools

Postfix access logs can be complicated and difficult to understand. You can try one of these Postfix log-analysis tools to help demystify the log files:

• Jimsun is a free, open-source tool that summarizes Postfix log entries: http://jimsun.linxnet.com/postfix_contrib.html.

• Sawmill is a commercial log-analysis tool that supports more than 500 different log types: http://www.sawmill.net/.