From PostgreSQL wiki
Posting for Postgres jobs is done by sending an email to the group email address email@example.com. When crafting your email, clearly state the employment location in the subject line, as this a global email list. If remote work is possible, mention that in your email as well.
Once a moderator approves your email, it will be sent to everyone subscribed to that email list. You can see your email posting by looking at the email list summary page. You should then start receiving private email replies to your job posting. (Replies should not go to the group email address.)