Aaron Poffenberger

My OpenSMTPD tutorial was accepted for BSDCan. I also have a BoF session.

Conference dates are June 9 - 10, 2017.

N.B. Tutorials are the two days before, June 7 - 8.

OpenSMTPD for the Real World (Tutorial)



I don't know yet which day the tutorial is on, but it will be June 7th or 8th.

Once the schedule is up I'll update this article.


This session is aimed at administrators who can't or won't use 3rd-party mail hosting (and who would?) but still need a reliable, spam- and virus-resistant mail server. A basic knowledge of BSD, smtp and dns is expected and required.

Full description

The session is a hands-on tutorial covering configuration and use of OpenSMTPD as the core of a spam- and virus-resistant mail server.

After this tutorial you will know how:

  • Configure smtpd as a Mail Transfer Agent (MTA) for single and multi-domain use
  • Install a certificate and configure smtpd to provide or require TLS
  • How to accept or reject mail based on criteria like recipient, source, sender and domain
  • How to tag mail
  • How to configure smtpd to work with Spam Assassin, ClamAV or Local-Mail-Transfer-Protocol (LMTP) services (in series or individually)
  • How to configure smtpd to deliver mail to Dovecot
  • Know how to troubleshoot smtpd issues using smtpd's syntax checker, logs and by sending mail manually via telnet

We'll also look at integration of OpenSMTPD with other spam-fighting services:

  • Simple pf configuration for spamd
  • Adding blacklist sources to spamd.conf
  • Updating spamd with OpenBGPD

New and updated for 2017:

  • Using a database to manage virtual users in both OpenSMTPD and Dovecot
  • Signing outbound email with DKIMproxy
  • Using spf_fetch to whitelist outbound mailers from Google, Microsoft, et al.

If there's time we'll also cover:

  • Configuring smtpd as a store-and-forward mail server
  • Configuring smtpd as a backup mail server
  • Using other features of smtpd to fold, spindle and mutilate unwanted mail

The instructor will conduct the tutorial on OpenBSD and will attempt to help students who want to use another BSD platform supported by OpenSMTPD.

The session is aimed primarily at single or low-mail-server-count environments but is open to anyone who wants to learn more about running OpenSMTPD for production mail services.

The session is meant to be hands on. To get the most out of it, please bring a laptop with OpenSMTPD, Spam Assassin and ClamAV installed and at least SQLite.


This is an updated version of my 2016 BSDCan tutorial.

Amateur Radio and SDR (BoF)


I don't have any details about BoF scheduling. I'll announce the details as I get them.


Amateur radio users and those curious about radio and SDR meet and discuss hardware, software, triumphs and challenges with pursuing the hobby on BSD.

Full description

Come talk all things amateur radio, SDR and porting. We'll have a short presentation about amateur radio and SDR and open the floor to questions, presentations on works-in-progress and hack.


I'll bring several SDR and handheld radios and encourage others to do the same.