Gen email commands are utility / convenience commands that are built on top of the tcllib mime and smtp packages.
To configure Gen for using certain email-related commands, you need to (A) add the following configuration code to your software, before you start using email commands, or (B) open src/gen-config.tcl or create your own src/gen-user-config.tcl and configure by hand the following (though beware of overwriting src/gen-config.tcl when you update your version of Gen):
set GenNS::SendEmail::Servers [Required. A list of SMTP servers. The default is localhost.]set GenNS::SendEmail::Port [Optional. A list of SMTP ports. The default is 25.]set GenNS::SendEmail::Username [Required. Username to use to authenticate with your mail server.]set GenNS::SendEmail::Password [Required. Password to authenticate with your mail server.]set GenNS::SendEmail::FromAddress [Required. Email address to use for the "From:" header.]set GenNS::SendEmail::UseTls [Optional. Boolean value. Controls whether or not the TLS extension is used. Requires the tls package be installed to be used.]set GenNS::SendEmail::Queue [Optional. Boolean value. Indicates that the SMTP server should be asked to queue the message for later processing.]set GenNS::SendEmail::AtLeastOne [Optional. Boolean value. Indicates that the SMTP server must find at least one recipient acceptable for the message to be sent.]set GenNS::GetEmailUsingImap4::Hostname [Required. Boolean value. Indicates the IMAP4 server which hosts the email account.]set GenNS::GetEmailUsingImap4::Port [Optional. Boolean value. Indicates the port number to use with IMAP4.]