sSMTP is a simple program that punts mail over to a mailhub. I use this on a few Ubuntu hosts. I recently deployed a Raspberry Pi running Raspian that I wanted to enable mail alerting with. I quickly found that it could not send e-mails with sSMTP. At first, I assumed it was my configuration but I investigated and found an issue with TLS handshakes.

sSMTP has a known (and fixed) problem with TLS 1.3 handshakes. According to the changelog, this was fixed in August 2019.

Enabling “testing” on Debian would likely bring more issues than I cared for, so I set out to build a package for my Buster hosts.

Build sSMTP package on Buster

  1. Download the files from debian

    $ wget
  2. Prepare for build

    $ tar jxvf ssmtp_2.64.orig.tar.bz2
    $ cd ssmtp-2.64/
    $ tar -jxvf ../ssmtp_2.64-9.debian.tar.bz2
  3. Install build dependencies

    • NOTE: build-essential is required, but part of raspian lite. You may need to add this to the list.
    $ sudo apt-get install po-debconf libgnutls-openssl-dev
  4. Generate a new debian package

    $ dpkg-buildpackage -b

    Congrats. You now have ssmtp_2.64-9_armhf.deb.

  5. Install the package

    $ sudo dpkg -i ssmtp_2.64-9_armhf.deb
    $ sudo apt-get install -f # If the above complains
  6. OPTIONAL Remove build dependencies

    $ sudo apt-get autoremove --purge po-debconf libssl-dev