Since each email you send requires a login through your outgoing client (e.g. SMTP), your emailer has to know the server address, security type (e.g. TLS), etc.

Since each email you send requires a login through your outgoing client (e.g. SMTP), your emailer has to know the server address, security type (e.g. TLS), etc. Most clients configure this the first time you try to send vis that server and store the credentials for future use. You only need change these settings if your server credentials change..