Administration ============== The Administration GUI allows you to do common tasks such as updating software packages, managing quarantine, viewing service status, and managing mail queues. It also provides server statistics in order to verify server health. Server Administration --------------------- Server status ~~~~~~~~~~~~~ [thumbnail="pmg-gui-server-status.png", big=1] This page shows server statistics about CPU, memory, disk and network usage. You can select the displayed time span on the upper right. Administrators can open a terminal window using the 'Console' button. It is also possible to trigger a server 'Restart' or 'Shutdown'. Services ~~~~~~~~ [thumbnail="pmg-gui-service-status.png", big=1] This panel lists all major services used for mail processing and cluster synchronization. If necessary, you can start, stop or restart them. The 'Syslog' button shows the system log filtered for the selected service. Please note that {pmg} uses {systemd} to manage services, so you can also use the standard `systemctl` command line tool to manage or view service status, for example: ----- systemctl status postfix ----- Updates ~~~~~~~ [thumbnail="pmg-gui-updates.png", big=1] We release software updates on a regular basis, and it is recommended to always run the latest available version. This page shows the available updates, and administrators can run an upgrade by pressing the 'Upgrade' button. See section xref:pmg_package_repositories[Package Repositories] for details abaout available package repositories. Syslog and Tasks ~~~~~~~~~~~~~~~~ [thumbnail="pmg-gui-syslog.png", big=1] The syslog page gives you a quick real-time log view. You can use the xref:pmg_tracking_center[Tracking Center] to search the logs. Quarantine ---------- Spam ~~~~ [thumbnail="pmg-gui-spam-quarantine.png", big=1] This panel lets you inspect the mail quarantine. Emails can be safely previewed and if desired, delivered to the original user. The email preview on the web interface is very secure as malicious code (attacking your operating system or email client) is removed by {pmg}. Virus ~~~~~ Allows administrators to inspect quarantined virus mails. Attachment ~~~~~~~~~~ Allows administrators to inspect quarantined mails and download their attachments or deliver/delete them. NOTE: Use the options of the 'Remove attachment' action to control the Attachment Quarantine. [[pmg_userblackwhitelist]] User White- and Blacklist ~~~~~~~~~~~~~~~~~~~~~~~~~ This is mostly useful to debug or verify white- and blacklist user settings. The administrator should not change these values because users can manage this themselves. [[pmg_tracking_center]] Tracking Center --------------- [thumbnail="pmg-gui-tracking-center.png", big=1] Email processing is a complex task and involves several service daemons. Each daemon logs information to the syslog service. The problem is that a server analyzes many emails in parallel, so it is usually very hard to find all logs corresponding to a specific mail. The Tracking Center simplifies the search for emails dramatically. We use highly optimized and safe Rust footnote:[A language empowering everyone to build reliable and efficient software. https://www.rust-lang.org/] code to search the available syslog data. This is very fast and powerful, and works for sites processing several million emails per day. The result is a list of received mails, including the following data: [cols="s,5d"] |==== |Time | Timestamp of first found syslog entry. |From | Envelope 'From' address (the sender). |To | The email receiver address. |Status | Delivery status. |Syslog | The corresponding syslog entries are shown if you double click such entry, or if you press the '+' button on the left. |==== You can specify filters, and most importantly you can set a 'Start' and 'End' time. By default the start time is set to one hour ago. If you still get too many entries, you can try to restrict the search to a specific sender or receiver address, or search for a specific text in the logs ('Filter' entry). NOTE: Search is faster if you use a shorter time interval. The 'Status' field summarizes what happened with an email. {pmg} is a mail proxy, meaning that the proxy receives mails from outside, processes them and finally sends the result to the receiver. The first phase is receiving the mail. The proxy may reject the mail early, or instead accepts the mail and feeds it into the filter. The filter rules can block or accept the mail. In the second phase, accepted mails need to be delivered to the receiver. This action may also fail or succeed. 'Status' combines the result from the first and second phase. When before-queue filtering is enabled, we don't have the same delivery information as with after-queue filtering. In this case, if the mail is accepted by the filter, the status is shown as 'queued/accepted' instead of 'accepted/'. [options="header",cols="2s,1d,5d"] |==== |Status |Phase |Description |rejected |1 | Email rejected (e.g. sender IP is listed on a IP blacklist) |greylisted |1 | Email temporarily rejected by greylisting |queued/deferred |1 | Internal Email was queued, still trying to deliver |queued/bounced |1 | Internal Email was queued but not accepted by the target email server (for example user unknown) |queued/accepted |1 | Email was accepted, no delivery information available (before-queue only, replaces accepted/) |quarantine |1 | Email was moved to quarantine |blocked |1 | Email was blocked by filter rules |accepted/deferred |2 | Email accepted, still trying to deliver |accepted/bounced |2 | Email accepted but not accepted by the target email server (for example user unknown) |accepted/delivered |2 | Email accepted and delivered |==== Postfix Queue Administration ---------------------------- Mail-queues are one of the central concepts of the SMTP protocol. Once a mailserver accepts a mail for further processing it saves it to a queue. After the mail is either relayed to another system, stored locally or discarded it is deleted from the local mail-queue. If immediate processing is not possible, for example because a downstream mailserver is not reachable, the mail remains on the queue for later processing. The Queue Administration view provides a succinct overview, as generated by the 'qshape (1)' utility, about the current state of the postfix mail-queue. It shows mails for which domains were not delivered, and how long they have been queued. The three Action Buttons on top provide the most common queue operations: 'Flush Queue':: Attempt to deliver all currently queued mail, for example if a downstream server has become available again. 'Delete All Messages':: Delete all currently queued mail, for example if the queue contains only spam. Attempt to deliver all currently queued mail. 'Discard address verification database':: Clear the recipient verification cache. In the 'Deferred Mail' tab you can filter and examine deferred mail in more detail by looking at the headers.