Deliver macOS system mail with the following instructions. These instructions apply to **macOS Catalina**.

## Why would you want to do this?

- You have cron jobs running on your system and want to receive emails when they fail.
- You want an email when certain things happen on your system through Automator or other means.

## Instructions

Edit the /etc/postfix/sasl_passwd file

```
sudo vi /etc/postfix/sasl_passwd
```

Add this line of text, and [create an app password].

```
[smtp.gmail.com]:587 <Your Email Id>@gmail.com:<Your App Password>
```

Run the postfix lookup table management command

```
sudo postmap /etc/postfix/sasl_passwd
```

Edit the /etc/postfix/main.cf file

```
sudo vi /etc/postfix/main.cf
```

Add these properties to the bottom of the file.

```
# Gmail SMTP relay
relayhost = [smtp.gmail.com]:587

# Enable SASL authentication in the Postfix SMTP client.
smtpd_sasl_auth_enable = yes
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options =
smtp_sasl_mechanism_filter = AUTH LOGIN

# Enable Transport Layer Security (TLS), i.e. SSL.
smtp_use_tls = yes
smtp_tls_security_level = encrypt
tls_random_source = dev:/dev/urandom
```

Test delivery of mail from your system

```
date | mail -s "Test Email" <Your Email Id>@gmail.com
```

If you don't receive an email, run this command before the previous command to debug the problem.

```
log stream --predicate  '(process == "smtpd") || (process == "smtp")' --info
```

[create an app password]: https://myaccount.google.com/security