IIS SMTP with SmartHost at SendGrid.Net...

Smarthost configuration to configure sSMTP to relay sendgrid...

Sendmail DSN Error - OLD TITLE(Sendmail Smart Host using TLS - host is rejecting)...

Sendmail + Smart Relay: don't forward mail to local accounts...

Add gmail as smarthost in Debian exim4...

sendmail never send mail. Always deffered...

Configuring sendmail behind a firewall...