Offbeat Internet
Public Access
SMTP
The Simple Mail Transfer Protocol (SMTP) is an email sending protocol. Due to abuses by spammers, SMTP servers are now almost never open relays. SMTP uses the URI "mailto:", which is supported by most Browsers. Below are addresses of SMTP servers on which registered access is freely given (each host has their own method of registration).
[IANA Port assignment = 25]
Note that most ISPs allow unregistered access to their own SMTP servers when connecting from one of their own IP addresses.