Ok, I screwed up. When I put in cram-md5 and digest-md5, I left the alternative as being "plain", which is a misnomer. There really IS a mechanism called "plain", and what we're doing isn't it. So I've renamed our "plain" to "login".

For IMAP, it uses the IMAP4rev1 "LOGIN <user> <pass>" syntax.
For SMTP, it uses the AUTH LOGIN (two-step) method.

class/deliver/Deliver_SMTP.class.php

@@ -104,8 +104,8 @@ class Deliver_SMTP extends Deliver {
 	  if ($this->errorCheck($tmp, $stream)) {
         return(0);
 	  }
-	} elseif ($smtp_auth_mech == 'plain') {
-	  // The plain LOGIN method
+	} elseif ($smtp_auth_mech == 'login') {
+	  // The LOGIN method
       fputs($stream, "EHLO $domain\r\n");
       $tmp = fgets($stream, 1024);
 	  if ($this->errorCheck($tmp, $stream)) {

config/conf.pl

@@ -346,7 +346,7 @@ if ( !$use_imap_tls ) {
 }
 
 if ( !$imap_auth_mech ) {
-    $imap_auth_mech = 'plain';
+    $imap_auth_mech = 'login';
 }
 
 if (!$session_name ) {
@@ -1130,14 +1130,14 @@ sub command111 {
     return $new_optional_delimiter;
 }
 # IMAP authentication type
-# Possible values: plain, cram-md5, digest-md5
+# Possible values: login, cram-md5, digest-md5
 # Now offers to detect supported mechs, assuming server & port are set correctly
 
 sub command112a {
 	print "If you have already set the hostname and port number, I can try to\n";
 	print "detect the mechanisms your IMAP server supports.\n";
 	print "I will try to detect CRAM-MD5 and DIGEST-MD5 support.  I can't test\n";
-	print "for \"plain\" without knowing a username and password.\n";
+	print "for \"login\" without knowing a username and password.\n";
 	print "Auto-detecting is optional - you can safely say \"n\" here.\n";
 	print "\nTry to detect supported mechanisms? [y/N]: ";
 	$inval=<STDIN>;
@@ -1172,15 +1172,15 @@ sub command112a {
 	  
 	} 
 	  print "\nWhat authentication mechanism do you want to use for IMAP connections?\n\n";
-	  print $WHT . "plain" . $NRM . " - Plaintext. If you can do better, you probably should.\n";
-	  print $WHT . "cram-md5" . $NRM . " - Slightly better than plaintext.\n";
+	  print $WHT . "login" . $NRM . " - Plaintext. If you can do better, you probably should.\n";
+	  print $WHT . "cram-md5" . $NRM . " - Slightly better than plaintext methods.\n";
 	  print $WHT . "digest-md5" . $NRM . " - Privacy protection - better than cram-md5.\n";
 	  print "\n*** YOUR IMAP SERVER MUST SUPPORT THE MECHANISM YOU CHOOSE HERE ***\n";
-	  print "If you don't understand or are unsure, you probably want \"plain\"\n\n";
-	  print "plain, cram-md5, or digest-md5 [$WHT$imap_auth_mech$NRM]: $WHT";
+	  print "If you don't understand or are unsure, you probably want \"login\"\n\n";
+	  print "login, cram-md5, or digest-md5 [$WHT$imap_auth_mech$NRM]: $WHT";
       $inval=<STDIN>;
       chomp($inval);
-      if ( ($inval =~ /^cram-md5\b/i) || ($inval =~ /^digest-md5\b/i) || ($inval =~ /^plain\b/i)) {
+      if ( ($inval =~ /^cram-md5\b/i) || ($inval =~ /^digest-md5\b/i) || ($inval =~ /^login\b/i)) {
         return lc($inval);
       } else {
         # user entered garbage or default value so nothing needs to be set
@@ -1203,7 +1203,7 @@ sub command112b {
 		print "Trying to detect supported methods (SMTP)...\n";
 		
 		# Special case!
-		# Check none by trying to relay to junk@birdbrained.org
+		# Check none by trying to relay to junk@microsoft.com
 		$host = $smtpServerAddress . ':' . $smtpPort;
 		use IO::Socket;
 		my $sock = IO::Socket::INET->new($host);
@@ -1214,7 +1214,7 @@ sub command112b {
 		} else {
 			print $sock "mail from: tester\@squirrelmail.org\n";
 			$got = <$sock>;  # Discard
-			print $sock "rcpt to: junk\@birdbrained.org\n";
+			print $sock "rcpt to: junk\@microsoft.com\n";
 			$got = <$sock>;  # This is the important line
 			if ($got =~ /^250\b/) {  # SMTP will relay without auth
 				print "SUPPORTED$NRM\n";
@@ -1225,8 +1225,8 @@ sub command112b {
 			print $sock "quit\n";
 			close $sock;
 		}
-		# Try plain (SquirrelMail default)
-		print "Testing plain:\t\t";
+		# Try login (SquirrelMail default)
+		print "Testing login:\t\t";
 		$tmp=detect_auth_support('SMTP',$host,'LOGIN');
 		if (defined($tmp)) {
         	if ($tmp eq 'YES') {
@@ -1266,12 +1266,12 @@ sub command112b {
     } 
     print "\tWhat authentication mechanism do you want to use for SMTP connections?\n";
     print $WHT . "none" . $NRM . " - Your SMTP server does not require authorization.\n";
-    print $WHT . "plain" . $NRM . " - Plaintext. If you can do better, you probably should.\n";
+    print $WHT . "login" . $NRM . " - Plaintext. If you can do better, you probably should.\n";
     print $WHT . "cram-md5" . $NRM . " - Slightly better than plaintext.\n";
     print $WHT . "digest-md5" . $NRM . " - Privacy protection - better than cram-md5.\n";
-    print "\n*** YOUR SMTP SERVER MUST SUPPORT THE MECHANISM YOU CHOOSE HERE ***\n";
+    print $WHT . "\n*** YOUR SMTP SERVER MUST SUPPORT THE MECHANISM YOU CHOOSE HERE ***\n" . $NRM;
     print "If you don't understand or are unsure, you probably want \"none\"\n\n";
-    print "none, plain, cram-md5, or digest-md5 [$WHT$smtp_auth_mech$NRM]: $WHT";
+    print "none, login, cram-md5, or digest-md5 [$WHT$smtp_auth_mech$NRM]: $WHT";
     $inval=<STDIN>;
     chomp($inval);
     if ($inval =~ /^none\b/i) {
@@ -1279,7 +1279,7 @@ sub command112b {
       return "none";
     }
     if ( ($inval =~ /^cram-md5\b/i) || ($inval =~ /^digest-md5\b/i) || 
-    ($inval =~ /^plain\b/i)) {
+    ($inval =~ /^login\b/i)) {
       return lc($inval);
     } else {
       # user entered garbage, or default value so nothing needs to be set
@@ -3076,9 +3076,16 @@ sub detect_auth_support {
         return undef;
     }
 	my $discard = <$sock>; # Server greeting/banner - who cares..
+
+	if ($service eq 'SMTP') {
+		# Say hello first..
+		print $sock "helo $domain\n";
+		$discard = <$sock>; # Yeah yeah, you're happy to see me..
+	}
 	print $sock $cmd;
 
 	my $response = <$sock>;
+	chomp($response);
 	if (!defined($response)) {
 		return undef;
 	}
@@ -3089,6 +3096,9 @@ sub detect_auth_support {
 			# Not supported
 			close $sock;
 			return 'NO';
+		} elsif ($response =~ /^503/) {
+			#Something went wrong
+			return undef;
 		}
 	} elsif ($service eq 'IMAP') {
 		if ($response =~ /^A01/) {

config/config_default.php

@@ -521,13 +521,13 @@ global $use_smtp_tls;
 $use_imap_tls = false;
 $use_smtp_tls = false;
 
-/* auth_mech can be either 'plain', 'cram-md5', or 'digest-md5'
+/* auth_mech can be either 'login','plain', 'cram-md5', or 'digest-md5'
    SMTP can also be 'none'
 */
 global $smtp_auth_mech;
 global $imap_auth_mech;
 $smtp_auth_mech = 'none';
-$imap_auth_mech = 'plain';
+$imap_auth_mech = 'login';
 
 /* PHP session name.  Leave this alone unless you know what you are doing. */
 global $session_name;

functions/auth.php

@@ -18,7 +18,7 @@ if (! isset($smtp_auth_mech)) {
 }
 
 if (! isset($imap_auth_mech)) {
-  $imap_auth_mech = 'plain';
+  $imap_auth_mech = 'login';
 }
 
 if (! isset($use_imap_tls)) {

functions/imap_general.php

@@ -238,7 +238,7 @@ function sqimap_login ($username, $password, $imap_server_address, $imap_port, $
     $password = OneTimePadDecrypt($password, $onetimepad);
 
 	if (($imap_auth_mech == 'cram-md5') OR ($imap_auth_mech == 'digest-md5')) {
-      // We're using some sort of authentication OTHER than plain
+      // We're using some sort of authentication OTHER than plain or login
 	  $tag=sqimap_session_id(false);
 	  if ($imap_auth_mech == 'digest-md5') {
 	    $query = $tag . " AUTHENTICATE DIGEST-MD5\r\n";
@@ -275,11 +275,13 @@ function sqimap_login ($username, $password, $imap_server_address, $imap_port, $
 		$message='IMAP server does not appear to support the authentication method selected.';
 		$message .= '  Please contact your system administrator.';
       }
-    } else {
-	  // Original PLAIN login code
+    } elseif ($imap_auth_mech == 'login') {
+	  // Original IMAP login code
       $query = 'LOGIN "' . quoteIMAP($username) .  '" "' . quoteIMAP($password) . '"';
       $read = sqimap_run_command ($imap_stream, $query, false, $response, $message);
-    }
+    } else {
+	  // Insert SASL PLAIN code here, if it ever gets implemented
+	}
     
 	/* If the connection was not successful, lets see why */
     if ($response != 'OK') {

plugins/administrator/defines.php

@@ -120,9 +120,10 @@ $defcfg = array( '$config_version' => array( 'name' => _("Config File Version"),
 										   'default' => false ),
 				 '$imap_auth_mech' => array( 'name' => _("IMAP Authentication Type"),
 				 							 'type' => SMOPT_TYPE_STRLIST,
-											 'posvals' => array('plain' => 'Plaintext',
+											 'posvals' => array('login' => 'IMAP LOGIN',
 											 				    'cram-md5' => 'CRAM-MD5',
-																'digest-md5' => 'DIGEST-MD5') ),
+																'digest-md5' => 'DIGEST-MD5'),
+											 'default' => 'login' ),
                  '$useSendmail' => array( 'name' => _("Use Sendmail Binary"),
                                           'type' => SMOPT_TYPE_BOOLEAN,
 										  'comment' => "Say 'no' for SMTP" ),
@@ -141,7 +142,7 @@ $defcfg = array( '$config_version' => array( 'name' => _("Config File Version"),
 				 '$smtp_auth_mech' => array( 'name' => _("SMTP Authentication Type"),
 				 							 'type' => SMOPT_TYPE_STRLIST,
 											 'posvals' => array('none' => 'No SMTP auth',
-											                    'plain' => 'Plaintext',
+											 					'login' => 'Login (Plaintext)',
 																'cram-md5' => 'CRAM-MD5',
 																'digest-md5' => 'DIGEST-MD5'),
 											 'default' => 'none'),