Status Update October 2021 —

Status Update October 2021

by Joshua Branson — November 01, 2021

The main thing that I have been working on this month is an opensmtpd-service that uses (guix records). The code is here. It has been a real pleasure creating the various records to turn this:

(service opensmtpd-service-type
            (compression #t)))
            (max-message-size "10M")))
            (ttl-delay "5d")))
          (pkis (list
                  (domain "")
                  (cert "/etc/letsencrypt/live/")
                  (key "/etc/letsencrypt/live/"))))
          (tables (list
                    (name "aliases")
                      (cons "webmaster" "root")
                      (cons "postmaster" "root")
                      (cons "abuse" "root"))))
                    (name "creds")
                      (cons "joshua"
                    (name "vdoms")
                    (values (list ""
                    (name "vusers")
                    (values (list (cons "" "joshua")
                                  (cons "" "joshua")
                                  (cons "" "joshua"))))))
            ;; this forum help suggests that I listen on and NOT eth0
            ;; this listens for email from the outside world
             (interface "eth0")
             (port 25)
             (secure-connection "tls")
             (pki ""))
            ;; this lets local users logged into the system via ssh send email
             (interface "lo")
             (port 25)
             (secure-connection "tls")
             (pki ""))
             (interface "eth0")
             (port 465)
             (secure-connection "smtps")
             (pki "")
             (auth "<creds>"))
             (interface "eth0")
             (port 587)
             (secure-connection "tls-require")
             (pki "")
             (auth "<creds>"))
               (name "receive")
                 (method (opensmtpd-maildir-configuration
                          (pathname "/home/%{rcpt.user}/Maildir")
                          (junk #t)))
                 (virtual "vusers"))))
             (name "send")
             (method (opensmtpd-relay-configuration)))))
          (matches (list
                     (name "send")
                     (for "for any")
                     (from "from any")
                     (auth "auth"))
                     (name "receive")
                     (from "from any")
                     (for "for domain <vdoms>"))
                     (name "receive")
                     (for "for local"))))
             (name "dropDumbEmails")
             (filter-names (list "nofcrdnsDisconnect"
           (list (opensmtpd-filter-phase
                  (name "nofcrdnsDisconnect")
                  (phase-name "connect")
                  (conditions (list "!fcrdns"))
                  (decision "disconnect")
                  (message "You have not set up forward confirmed DNS."))
                  (name "nordnsDisconnect")
                  (phase-name "connect")
                  (conditions (list "!rdns"))
                  (decision "reject")
                  (message "You have not set up reverse DNS."))))))

into this:

smtp max-message-size 10M

srs ttl 5d

queue compression

table aliases { "webmaster" = "root", "postmaster" = "root", "abuse" = "root" }
table creds { "joshua" = "$6$Ec4m8FgKjT2F/03Y$k66ABdse9TzCX6qaALB3WBL9GC1rmAWJmaoSjFMpbhzat7DOpFqpnOwpbZ34wwsQYIK8RQlqwM1I/v6vsRq86." }
table vdoms { "", "" }
table vusers { "" = "joshua", "" = "joshua", "" = "joshua" }

pki cert "/etc/letsencrypt/live/"
pki key "/etc/letsencrypt/live/"

filter "nofcrdnsDisconnect" phase connect match !fcrdns disconnect "You have not set up forward confirmed DNS."
filter "nordnsDisconnect" phase connect match !rdns reject "You have not set up reverse DNS."

filter "dropDumbEmails" chain {nofcrdnsDisconnect, nordnsDisconnect}

listen on eth0 tls port 25 pki
listen on lo tls port 25 pki
listen on eth0 smtps port 465 pki auth <<creds>>
listen on eth0 tls-require port 587 pki auth <<creds>>

action "receive" maildir "/home/%{rcpt.user}/Maildir" junk
action "send" relay

match from any for any auth tls action "send"
match from any for domain <vdoms> tls action "receive"
match for local tls action "receive"

Looking at it now, one might almost prefer just to use the opensmtpd configuration syntax. Still it is nice to be able to use a schemey syntax and translate in into something that opensmtpd can parse. Perhaps someone could potentially configure a webserver via something like this:

(service email-service-type
          (domains (list ""
          (use-letsencrypt-certs #t)))

Perhaps the above would set up a DNS server at And serve the emails via dovecot. Though that would be a task for someone else.

Future work for my opensmtpd-service via (guix records) includes writing figure out how to let opensmtpd-filter-proc-exec accept a list of strings and gexps. I currently could use my opensmtpd-service for my linode server via the includes directive, but I'd rather use the opensmtpd-filter-proc-exec. My current opensmtpd configuration can be found here. If you can think of anyway that I can improve the code, please reach out: jbranso AT dismail DOT de.

I made a cookbook submission about auto logging into tty3

This was a while ago, but I did write an entry in the cookbook about how to autologin to a specific tty. So if you want to learn how to auto login to sway via guix system, this is part of that solution.

I am now hosting an xmpp account on

My account delivers SMS text messages to my XMPP account at via Perhaps one day soon, I'll be able to host my own chats via That would be pretty awesome!

Guix's official libreboot cookbook guide

I also need to finish Raghav's libreboot cookbook guide for inclusion to the guix cookbook.