I'd like to use nullmailer to have my Debian (bullseye and bookworm) systems send system-generated email messages to the appropriate recipient. nullmailer is configured (among others) by the file /etc/nullmailer/remotes that contains the following line:
smtp.example.org smtp starttls x509cafile=/etc/nullmailer/smtp.example.org.crt --user=me --pass='mypassword'
According to the manual (man nullmailer-send), the password must be enclosed in single quotes ('), and a quick test confirms that this is needed.
However, some of my passwords for SMTP authentication already contain single quotes. Writing them literally in the configuration file of course does not work. Quoting them with a backslash (\', as is common in other applications), or doubling them to quote them ('', as is also common in other applications) does not work either. In every case, nullmailer reports an SMTP authentication error.
How do I quote single quotes in the SMTP password in nullmailer's /etc/nullmailer/remotes configuration file?
In case it matters: Some of these passwords contain single quotes as well as double quotes (").
