SMTP is used for the transmission of email on the Internet. A vast majority of Web Hosting Service Providers are discontinuing the practice of providing unrestricted outgoing SMTP, largely due to nearly impossible access control, and thus its high vulnerability to spam, abuse and denial of service attacks.
However, SMTP service can be provided to authorized users via authentication. This means that the SMTP mail server 'knows' who you are, either because you are within the same network as the mail server, or you have provided a username and password to use it.
As a fundamental Internet service, this is something that is already provided to you by your dial-up Internet Service Provider. Since you are connecting to the Internet through your ISP's network, their SMTP server is able to identify you as an authorized user. We recommend that you use you ISP's SMTP server where you can as you are already on their network and sending mail would be marginally quicker.
Another means of validating users for sending outgoing mail via SMTP is a newer method called SMTP Authentication. SMTP AUTH is now required to send mail through telivo's mail serveri (ie through your domain name, as we have mentioned in our setup guides). This allows our mail server to verify that any mail it is asked to deliver is actually originating from a valid user to whom we have granted mail server privileges and own domain names with us. It does this by requiring your e-mail software to support SMTP AUTH (a configurable option in your mail software settings) thereby sending your e-mail username and encrypted password before transmitting outgoing mail.
SMTP AUTH is currently supported by newer e-mail client software programs such as MS Outlook Express, MS Outlook and a few others. See below for step-by-step guides for setting up SMTP AUTH on the most popular e-mail clients.