hacks

LXC scripts for unprivileged containers

Handling LXC unprivileged containers as root is not possible with the default LXC programs, because they must be called by the user who owns them and sometime is also necessary to specify the container's configuration file. For example, running lxc-ls as root...

Denying bad DNS HELO/EHLOs

The RFC-821 Section 3.5 states that  The sender-SMTP MUST ensure that the <domain> parameter in a HELO command is a valid principal host domain name for the client host. As a result, the receiver-SMTP will not have to perform MX resolution on...

Playing with qmail-spp

qmail-spp provides plug-in support for qmail-smtpd. It allows you to write external programs and use them to check SMTP command argument validity. The plug-in can trigger several actions, like denying a command with an error message, logging data, adding a header...

Dovecot vpopmail-auth driver removal. Migrating to the SQL driver

Those who are still using the Dovecot's vpopmail auth driver should consider a migration to another backend, as on January 4, 2021 dovecot-2.3.13 was released and the vpopmail auth driver removed (more info here). I'll show below how to support domain aliases...