ProtoMon

ProtoMon is an easy-to-use server monitoring tool that will automatically check your servers and notify you if some of them are down. The following protocols are supported: ICMP, HTTP(S), FTP(S), POP3(S), IMAP(S), SMTP(S), Telnet(SSH) and SFTP. If a server is down, ProtoMon will perform some of these actions: display a pop-up notification window, play a sound, send a notification e-mail message.