==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.0
- Deployed with iRedMail Easy or the downloadable installer? the downloadable installer
- Linux/BSD distribution name and version: Ubuntu 18.04 LTS
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

I was trying to have SpamAssassin work with Postfix. I'd set up the SpamAssassin milter in Postfix.

Then I sent an email to support@mydomain.com hosted on the email server, expecting to see some X-Spam-Status email header inserted by SpamAssassin.

However, there was none there. A look into /var/log/maillog gave:

Dec 20 10:41:51 mail spamd[5494]: spamd: connection from ::1 [::1]:39186 to port 783, fd 5
Dec 20 10:41:51 mail spamd[5494]: spamd: handle_user (getpwnam) unable to find user: 'support'
Dec 20 10:41:51 mail spamd[5494]: spamd: still running as root: user not specified with -u, not found, or set to root, falling back to nobody
Dec 20 10:41:51 mail spamd[5494]: spamd: processing message <CA+=LkNExPgUGEt1a16xxxrUndUE_w4P_X=AeE2=hFxziwRkzkQ@mail.gmail.com> for support:65534
Dec 20 10:41:52 mail spamd[5494]: plugin: eval failed: bayes: (in learn) locker: safe_lock: cannot create lockfile /nonexistent/.spamassassin/bayes.mutex: No such file or directory
Dec 20 10:41:52 mail spamd[5494]: spamd: clean message (-0.2/5.0) for support:65534 in 0.4 seconds, 2578 bytes.
Dec 20 10:41:52 mail spamd[5494]: spamd: result: . 0 - DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,HTML_MESSAGE,UNPARSEABLE_RELAY scantime=0.4,size=2578,user=support,uid=65534,required_score=5.0,rhost=::1,raddr=::1,rport=39186,mid=<CA+=LkNExPgUGEt1a16xxxrUndUE_w4P_X=AeE2=hFxziwRkzkQ@mail.gmail.com>,autolearn=unavailable autolearn_force=no

Looks like spamd wasn't able to find the user support, and unable to create the bayes mutext.

Any idea how I can fix this?