I have a slow distant mail relay server and a web application I'm using locks up when sending e-mails to that distant mail server, until the e-mail is sent. After the e-mail is sent the page comes back and the application is snappy again.

SO I'm trying to set up a differed mail queue locally on the application server (linux) so that the application uses that instead of the distant mail server. My rationale is that e-mails would get queued up locally until they are processed by the distant mail server, but at least the application doesn't lock up.

I have installed postfix and set up the relayhost setting to the distant mail server, but performance has not improved. What appears to happen is that postfix just forwards my SMTP instructions in real time and doesn't really queue them?

What can I do?

Thanks!