Ben Johnson ben@indietorrent.org writes:

I added debugging output to the script, which now prints the environment variables. My script now outputs the following: ... CONFIG_FILE=/var/run/dovecot/config ... Does anything jump-out at you?

You didn't provide the analogous output from the interactive shell to see the differences (for example, USER might be being used), but from your later strace, I guess CONFIG_FILE has something to do with it.

These threads seems relevant

http://www.dovecot.org/list/dovecot/2011-May/059127.html
http://www.mail-archive.com/dovecot@dovecot.org/msg38349.html

That thread poster solved his problem by commenting out

service imap-postlogin {
# user = $default_internal_user
...
}

but I have no idea if it works, or whether it's a good idea, for your case. More docs

http://wiki2.dovecot.org/PostLoginScripting

Joseph Tam jtam.home@gmail.com