diff --git a/README.md b/README.md
index 2f25970..cf455a7 100644
--- a/README.md
+++ b/README.md
@@ -8,6 +8,8 @@ This draws heavily on Sovereign by Alex Payne (https://github.com/al3x/sovereign
 Deploying to EC2 from the command line
 --------------------------------------
 
+Amazon's EC2 isn't a great place to host a mail server. Do you still need to request permission to send email first? And you don't know if you'll get an IP address with a bad reputation from its previous owner. But it makes deployment easy, so it may at least be useful for testing.
+
 Sign up for Amazon Web Services.
 
 Create an Access Key at https://console.aws.amazon.com/iam/home?#security_credential. Download the key and save the information somewhere secure.
@@ -53,6 +55,8 @@ Somehow download these files.
 	sh scripts/index.sh
 	...
 	logout
+	
+You'll also want to set reverse DNS (PTR), which is something your hosting provider will probably have a control panel for.
 
 Terminate your instance with:
 
diff --git a/scripts/mail.sh b/scripts/mail.sh
index 45443fb..3cdf6ce 100755
--- a/scripts/mail.sh
+++ b/scripts/mail.sh
@@ -109,17 +109,22 @@ EOF
 sed -i "s/#port = 143/port = 0/" /etc/dovecot/conf.d/10-master.conf
 sed -i "s/#port = 110/port = 0/" /etc/dovecot/conf.d/10-master.conf
 
-# Modify the unix socket for LMTP.
-sed -i "s/unix_listener lmtp \(.*\)/unix_listener \/var\/spool\/postfix\/private\/dovecot-lmtp \1\n    user = postfix\n    group = postfix\n/" /etc/dovecot/conf.d/10-master.conf 
-
-# Add an additional auth socket for postfix. Check if it already is
-# set to make sure this is idempotent.
-if grep -q "mailinabox-postfix-private-auth" /etc/dovecot/conf.d/10-master.conf; then
-	# already done
-	true;
-else
-	sed -i "s/\(\s*unix_listener auth-userdb\)/  unix_listener \/var\/spool\/postfix\/private\/auth \{ # mailinabox-postfix-private-auth\n    mode = 0666\n    user = postfix\n    group = postfix\n  \}\n\1/" /etc/dovecot/conf.d/10-master.conf
-fi
+# Create a Unix domain socket specific for postgres to connect via LMTP because
+# postgres is already configured to use this location, and create a TCP socket
+# for spampd to inject mail on (if it's configured later). dovecot's standard
+# lmtp unix socket is also listening.
+cat > /etc/dovecot/conf.d/99-local.conf << EOF;
+service lmtp {
+  unix_listener /var/spool/postfix/private/dovecot-lmtp {
+    user = postfix
+    group = postfix
+  }
+  inet_listener lmtp {
+    address = 127.0.0.1
+    port = 10026
+  }
+}
+EOF
 
 # Drew Crawford sets the auth-worker process to run as the mail user, but we don't care if it runs as root.
 
diff --git a/scripts/spamassassin.sh b/scripts/spamassassin.sh
new file mode 100644
index 0000000..6a8ebc4
--- /dev/null
+++ b/scripts/spamassassin.sh
@@ -0,0 +1,48 @@
+# Spam filtering with spamassassin via spampd.
+
+apt-get -q -y install spampd dovecot-antispam
+
+# Hook into postfix. Replace dovecot with spampd as the mail delivery agent.
+tools/editconf.py /etc/postfix/main.cf virtual_transport=lmtp:[127.0.0.1]:10025
+
+# Hook into dovecot. This is actually the default but we don't want to lose track of it.
+tools/editconf.py /etc/default/spampd DESTPORT=10026
+
+# Automatically move spam into a folder called Spam. Enable the sieve plugin.
+# (Note: Be careful if we want to use multiple plugins later.)
+# The sieve scripts are installed by users_update.sh.
+sudo sed -i "s/#mail_plugins = .*/mail_plugins = \$mail_plugins sieve/" /etc/dovecot/conf.d/20-lmtp.conf
+
+# Enable the antispam plugin to detect when a message moves between folders so we can
+# pass it to sa-learn for training. (Be careful if we use multiple plugins later.)
+sudo sed -i "s/#mail_plugins = .*/mail_plugins = \$mail_plugins antispam/" /etc/dovecot/conf.d/20-imap.conf
+
+# When mail is moved in or out of the dovecot Spam folder, re-train.
+# from http://wiki2.dovecot.org/Plugins/Antispam
+cat > /usr/bin/sa-learn-pipe.sh << EOF;
+cat<&0 >> /tmp/sendmail-msg-\$\$.txt
+/usr/bin/sa-learn \$* /tmp/sendmail-msg-\$\$.txt > /dev/null
+rm -f /tmp/sendmail-msg-\$\$.txt
+exit 0
+EOF
+
+chmod a+x /usr/bin/sa-learn-pipe.sh
+
+cat > /etc/dovecot/conf.d/99-local-spampd.conf << EOF;
+plugin {
+    antispam_backend = pipe
+    antispam_spam_pattern_ignorecase = SPAM
+    antispam_allow_append_to_spam = yes
+    antispam_pipe_program_spam_arg = /usr/bin/sa-learn-pipe.sh --spam
+    antispam_pipe_program_notspam_arg = /usr/bin/sa-learn-pipe.sh --ham
+    antispam_pipe_program = /bin/bash
+}
+EOF
+
+# Initial training?
+# sa-learn --ham storage/mail/mailboxes/*/*/cur/
+# sa-learn --spam storage/mail/mailboxes/*/*/.Spam/cur/
+
+sudo service spampd restart
+sudo service dovecot restart
+
diff --git a/scripts/users_update.sh b/scripts/users_update.sh
new file mode 100644
index 0000000..4e5f768
--- /dev/null
+++ b/scripts/users_update.sh
@@ -0,0 +1,22 @@
+# Install dovecot sieve scripts to automatically move spam into the Spam folder.
+
+db_path=$STORAGE_ROOT/mail/users.sqlite
+
+for user in `echo "SELECT email FROM users;" | sqlite3 $db_path`; do
+	maildir=`echo $user | sed "s/\(.*\)@\(.*\)/\2\/\1/"`
+	
+	# Write the sieve file to move mail classified as spam into the spam folder.
+	mkdir -p $STORAGE_ROOT/mail/mailboxes/$maildir; # in case user has not received any mail
+	cat > $STORAGE_ROOT/mail/mailboxes/$maildir/.dovecot.sieve << EOF;
+require ["regex", "fileinto", "imap4flags"];
+
+if allof (header :regex "X-Spam-Status" "^Yes") {
+  setflag "\\\\Seen";
+  fileinto "Spam";
+  stop;
+}
+EOF
+
+
+done
+
diff --git a/tests/imap.py b/tests/imap.py
index e37c68d..af3442a 100644
--- a/tests/imap.py
+++ b/tests/imap.py
@@ -1,7 +1,9 @@
 import imaplib, os
 
+username = "testuser@" + os.environ.get("DOMAIN", "testdomain.com")
+
 M = imaplib.IMAP4_SSL(os.environ["INSTANCE_IP"])
-M.login("testuser@testdomain.com", "testpw")
+M.login(username, "testpw")
 M.select()
 print("Login successful.")
 typ, data = M.search(None, 'ALL')
diff --git a/tests/smtp.py b/tests/smtp_submission.py
similarity index 100%
rename from tests/smtp.py
rename to tests/smtp_submission.py
diff --git a/tools/editconf.py b/tools/editconf.py
index c7e3af5..e5e8d87 100755
--- a/tools/editconf.py
+++ b/tools/editconf.py
@@ -4,20 +4,27 @@ import sys, re
 
 # sanity check
 if len(sys.argv) < 3:
-	print("usage: python3 editconf.py /etc/file.conf NAME=VAL [NAME=VAL ...]")
+	print("usage: python3 editconf.py /etc/file.conf [-s] NAME=VAL [NAME=VAL ...]")
 	sys.exit(1)
 
 # parse command line arguments
 filename = sys.argv[1]
 settings = sys.argv[2:]
 
+delimiter = "="
+delimiter_re = r"\s*=\s*"
+if settings[0] == "-s":
+	settings.pop(0)
+	delimiter = " "
+	delimiter_re = r"\s+"
+
 # create the new config file in memory
 found = set()
 buf = ""
 for line in open(filename):
 	for i in range(len(settings)):
 		name, val = settings[i].split("=", 1)
-		m = re.match("\s*" + re.escape(name) + "\s*=\s*(.*?)\s*$", line)
+		m = re.match("\s*" + re.escape(name) + delimiter_re + "(.*?)\s*$", line)
 		if m:
 			# If this is already the setting, do nothing.
 			if m.group(1) == val:
@@ -33,7 +40,7 @@ for line in open(filename):
 				break
 			
 			# add the new setting
-			buf += name + "=" + val + "\n"
+			buf += name + delimiter + val + "\n"
 			
 			# note that we've applied this option
 			found.add(i)
@@ -46,7 +53,8 @@ for line in open(filename):
 # Put any settings we didn't see at the end of the file.
 for i in range(len(settings)):
 	if i not in found:
-		buf += settings[i] + "\n"
+		name, val = settings[i].split("=", 1)
+		buf += name + delimiter + val + "\n"
 
 # Write out the new file.
 with open(filename, "w") as f: