+ ####### begin dovecot setup ########
+ # based on a little google and package search, just the dovecot
+ # packages we need instead of dovecot-common.
+ #
+ # dovecot-lmtpd is for exim to deliver to dovecot instead of maildir
+ # directly. The reason to do this is to use dovecot\'s sieve, which
+ # has extensions that allow it to be almost equivalent to exim\'s
+ # filter capabilities, some ways probably better, some worse, and
+ # sieve has the benefit of being supported in postfix and
+ # proprietary/weird environments, so there is more examples on the
+ # internet. I was torn about whether to do this or not, meh.
+ pi dovecot-core dovecot-imapd dovecot-sieve dovecot-lmtpd
+
+ for f in /p/c/subdir_files/sieve/*sieve /a/c/subdir_files/sieve/*sieve; do
+ sudo -u $u /a/exe/lnf -T $f $(eval echo ~$u)/sieve/${f##*/}
+ done
+ # if we changed 90-sieve.conf and removed the active part of the
+ # sieve option, we wouldn\'t need this, but I\'d rather not modify a
+ # default config if not needed. This won\'t work as a symlink in /a/c
+ # unfortunately.
+ sudo -u $u /a/exe/lnf -T sieve/main.sieve $(eval echo ~$u)/.dovecot.sieve
+
+ # we set this later in local.conf
+ sed -ri -f - /etc/dovecot/conf.d/10-mail.conf <<'EOF'
+/^\s*mail_location\s*=/d
+EOF
+
+ cat >/etc/dovecot/conf.d/20-lmtp.conf <<EOF
+protocol lmtp {
+#per https://wiki2.dovecot.org/Pigeonhole/Sieve/Configuration
+ mail_plugins = \$mail_plugins sieve
+# default was
+ #mail_plugins = \$mail_plugins
+
+# For a normal setup with exim, we need something like this, which
+# removes the domain part
+# auth_username_format = %Ln
+#
+# or else # Exim says something like
+# "LMTP error after RCPT ... 550 ... User doesn't exist someuser@somedomain"
+# Dovecot verbose log says something like
+# "auth-worker(9048): passwd(someuser@somedomain): unknown user"
+# reference: http://wiki.dovecot.org/LMTP/Exim
+#
+# However, I use this to direct all mail to the same inbox.
+# A normal way to do this, which I did at first is to have
+# a router in exim almost at the end, eg 950,
+#local_catchall:
+# debug_print = "R: catchall for \$local_part@\$domain"
+# driver = redirect
+# domains = +local_domains
+# data = $u
+# based on
+# http://blog.alteholz.eu/2015/04/exim4-and-catchall-email-address/
+# with superflous options removed.
+# However, this causes the envelope to be rewritten,
+# which makes filtering into mailboxes a little less robust or more complicated,
+# so I've done it this way instead. it also requires
+# modifying the local router in exim.
+ auth_username_format = $u
+}
+
+EOF