Mail

Unlike esmtp, using your ISP's SMTP server with postfix will still allow local mail to be delivered. Any hosts listed in the mydestination option will be exempt from the SMTP relay.

Set up ISP info

Create /etc/postfix/sasl_passwd, like so:

Protect this file, since it has a plaintext password:

Create sasl_passwd DB file

Replace domU below with the hostname of your virtual machine and username with your personal user account.

On domU

Install a mail transfer agent and imap server

Set up postfix

Create a /etc/postfix/virtual file with entries like so:

Generate the virtual.db:

Tell postfix about your new virtual setup by adding the following to /etc/postfix/main.cf:

esmtp is a drop-in replacement for sendmail. If you're on DSL and everyone in the world blacklists your IP, you can set up esmtp with your DSL-provided SMTP information and continue sending mail as usual.

Install

Configure

Edit /etc/esmtprc. You'll probably just need to change hostname, username, and password.

Link it up