Simple Server Monitor
Simple Server Monitor is a powerful, yet easy to use server monitoring utility. It allows you to monitor the status of your servers and web applications from your desktop. Simple Server Monitor runs as a notification icon and you will be unaware that it is running - until a monitor fails. ... Simple Server Monitor also supports performance monitoring by charting the monitor response time and by logging (optional) all monitor queries to a log file and/or the event log. ... Supports Ping, HTTP/HTTP, FTP/FTPS, SMTP/SMTPS, POP3/POP3S, IMAP/IMAPS, and Custom monitors (supports SSL/TLS).
http://www.simpleservermonitor.com/files/setup.exe - 4Mb - Download - Screenshot

SMTP Watcher
SMTP Watcher is a tool designed to monitor your SMTP servers. This program is mainly intended for use by web administrators and server administrators. Your SMTP server is the one that is responsible for incoming mail. If it goes down, then people won't be able to send you mail. ... SMTP Watcher sits in the windows system tray and continuously polls your SMTP server to make sure it is online.
http://www.sb-software.com/smtpwatcher/sbsmtp10.exe - 615Kb - Download - Screenshot

Easy Network Service Monitor
Easy Service Monitor is a network fault management tool that continuously monitors network devices and services. If something went wrong, it will alert you by email/phone/pager BEFORE problems get seriously out of hand. A detailed log file will record every event of the monitored targets and can... You can configure the system so that when something goes wrong, a set of actions, such as execute a program, reboot server or update web page, will be triggered.
http://www.javvin.com/emonitor.exe - 2Mb - Download - Screenshot

PA Server Monitor
PA Server Monitor is a Windows service that monitors the health and availability of Windows servers, network services (on Windows, Linux and other operating systems), and devices. No agents are needed to monitor remote servers. Also includes rich reporting on most monitored resources. ... PA Server Monitor can watch: Event logs on local and remote Windows servers CPU and memory usage Free local and server disk space Changed files and directories (great intrusion detection) Running Windows services Custom script results Local and remote directory quota monitoring Network Interface...
http://www.poweradmin.com/servermonitor/servermonitorpro.exe - 5Mb - Download - Screenshot

PA Server Monitor Free Edition
PA Server Monitor has powerful features that are very simple to setup. The Free edition monitors web pages, ping response and the Windows event log, and response actions that can send SMTP email notifications, reboot the server, and more. Reports can be generated about most monitored resources. ... See Server Monitor at PowerAdmin. ... Our smart alerting will tell you about a particular problem once, and then tell you when it is fixed (instead of the constant stream of mindless 'still broke' messages that other products send).
http://www.poweradmin.com/servermonitor/servermonitorfree.exe - 5Mb - Download - Screenshot

IPCheck Server Monitor
IPCheck Server Monitor 5 helps organizations monitor critical network resources and immediately detect system failures or performance problems. It offers reliable network and website monitoring using Paessler's IPCheck? Technology, fast and easy installation, support for Windows NT/2000/XP/2003... Various sensor types including PING, PORT, HTTP, HTTPS, Advanced HTTP, HTTP Transaction, DNS, SMTP, POP3, SNMP and custom sensors are supported for in depth monitoring of almost any network device. ... The Freeware Edition monitors up to three sensors and is limited to PING, PORT and HTTP sensors...
http://download2.paessler.com/download/ipcheck.zip - 16Mb - Download - Screenshot

GFI Network Server Monitor
GFI Network Server Monitor automatically monitors the network & servers for failures. It allows you to identify issues and fix unexpected conditions before your users (or managers) report them to you! Alerts can be sent by email, pager or SMS, for instant problem notification. ... You can also write custom monitor functions in VBscript and leverage ADSI and WMI, allowing you to monitor virtually anything. ... GFI Network Server Monitor is easy to set up and use, and is competitively priced. ... Built-in monitoring rules include: Exchange Server 2000/2003, MS SQL, Oracle and ODBC databases,...
http://software.gfi.com/networkservermonitor7.exe - 13Mb - Download - Screenshot

NetStatus
NetStatus is a monitoring application designed to monitor anywhere from 1 to 50 servers or devices on a network. NetStatus has multiple test types that cover anything you might want to monitor on your network. Tests include HTTP, FTP, Telnet, Ping, Disk Space, NT Service Status, POP3, SMTP and... The user simply installs and opens their browser. ... Use intuitive lookups to speed up test configuration. ... Because it uses XML to store all data collected, there is not a heavy database overhead involved in setup.
http://www.otosoftware.com/downloads/ns.exe - 6Mb - Download - Screenshot

MailMonitor
MailMonitor is a program enabling you to monitor incoming and outgoing mail traffic to and from you mail server and clients. It tracks, displays and logs incoming and outgoing SMTP sessions, POP sessions and sent and received e-mails. It can store incoming and outgoing e-mail in a separate... Monitor SMTP authentication with IP, username and password. ... Monitor POP authentication. ... Watch for unsolicited mail forwarding, SMTP hacking (spammers that use your server to send their messages) and a host of other e-mail server related problems.
http://www.digiarch.org/download/mailmonitor.zip - 2Mb - Download - Screenshot

Sentry-go Quick File Monitor
The Sentry-go Quick File Monitor allows you to quickly & easily monitor changes made to both local and remote files, the contents of those files, directory changes & structure modifications, entries written to local Event Logs. If problems are detected, it can either take automatic action, or... Monitoring Features: The availability of local or remote files or directories; Check the overall size of a file, some or files all files or directories/sub-directories; Be alerted when a file is updated within a given timeframe, or when no changes are made to a file - ideal to ensure files are...
http://www.3ds.co.uk/sentry-go/shareware/qfile.exe - 4Mb - Download - Screenshot