diff -ur dovecot-1.0.5/src/imap/client.c dovecot-1.0.5-debugcmd/src/imap/client.c
--- dovecot-1.0.5/src/imap/client.c	2007-08-25 04:35:29.000000000 +1200
+++ dovecot-1.0.5-debugcmd/src/imap/client.c	2007-10-11 11:54:22.000000000 +1300
@@ -13,6 +13,8 @@
 
 extern struct mail_storage_callbacks mail_storage_callbacks;
 
+char **imap_debug_client_commands_arr;
+
 static struct client *my_client; /* we don't need more than one currently */
 static struct timeout *to_idle;
 
@@ -21,6 +23,10 @@
 {
 	struct client *client;
 
+	imap_debug_client_commands_arr = NULL;
+	if (getenv("IMAP_DEBUG_CLIENT_COMMANDS") != NULL)
+		imap_debug_client_commands_arr = t_strsplit_spaces(getenv("IMAP_DEBUG_CLIENT_COMMANDS"), ", ");
+
 	/* always use nonblocking I/O */
 	net_set_nonblock(fd_in, TRUE);
 	net_set_nonblock(fd_out, TRUE);
@@ -337,6 +343,8 @@
 
 static bool client_handle_input(struct client_command_context *cmd)
 {
+	int i;
+
 	struct client *client = cmd->client;
 
         if (cmd->func != NULL) {
@@ -385,6 +393,15 @@
 	} else {
 		/* find the command function */
 		cmd->func = command_find(cmd->name);
+
+		if (imap_debug_client_commands_arr != NULL) {
+			for (i = 0; imap_debug_client_commands_arr[i] != NULL; i++) {
+				if (strcasecmp(cmd->name, imap_debug_client_commands_arr[i]) == 0) {
+					i_info("Client command: %s", cmd->name);
+					break;
+				}
+			}
+		}
 	}
 
 	client->input_skip_line = TRUE;
diff -ur dovecot-1.0.5/src/master/mail-process.c dovecot-1.0.5-debugcmd/src/master/mail-process.c
--- dovecot-1.0.5/src/master/mail-process.c	2007-07-21 19:02:34.000000000 +1200
+++ dovecot-1.0.5-debugcmd/src/master/mail-process.c	2007-10-11 11:54:22.000000000 +1300
@@ -252,6 +252,10 @@
 		env_put("MAILDIR_COPY_PRESERVE_FILENAME=1");
 	if (set->mail_debug)
 		env_put("DEBUG=1");
+	if (*set->pop3_debug_client_commands != '\0')
+		env_put(t_strconcat("POP3_DEBUG_CLIENT_COMMANDS=", set->pop3_debug_client_commands, NULL));
+	if (*set->imap_debug_client_commands != '\0')
+		env_put(t_strconcat("IMAP_DEBUG_CLIENT_COMMANDS=", set->imap_debug_client_commands, NULL));
 	if (set->mail_full_filesystem_access)
 		env_put("FULL_FILESYSTEM_ACCESS=1");
 	if (set->pop3_no_flag_updates)
diff -ur dovecot-1.0.5/src/master/master-settings-defs.c dovecot-1.0.5-debugcmd/src/master/master-settings-defs.c
--- dovecot-1.0.5/src/master/master-settings-defs.c	2007-07-16 07:51:07.000000000 +1200
+++ dovecot-1.0.5-debugcmd/src/master/master-settings-defs.c	2007-10-11 11:54:22.000000000 +1300
@@ -66,6 +66,8 @@
 	DEF(SET_INT, mail_cache_min_mail_count),
 	DEF(SET_INT, mailbox_idle_check_interval),
 	DEF(SET_BOOL, mail_debug),
+	DEF(SET_STR, pop3_debug_client_commands),
+	DEF(SET_STR, imap_debug_client_commands),
 	DEF(SET_BOOL, mail_full_filesystem_access),
 	DEF(SET_INT, mail_max_keyword_length),
 	DEF(SET_BOOL, mail_save_crlf),
diff -ur dovecot-1.0.5/src/master/master-settings.c dovecot-1.0.5-debugcmd/src/master/master-settings.c
--- dovecot-1.0.5/src/master/master-settings.c	2007-07-16 07:51:07.000000000 +1200
+++ dovecot-1.0.5-debugcmd/src/master/master-settings.c	2007-10-11 11:54:22.000000000 +1300
@@ -215,6 +215,8 @@
 	MEMBER(mail_cache_min_mail_count) 0,
 	MEMBER(mailbox_idle_check_interval) 30,
 	MEMBER(mail_debug) FALSE,
+	MEMBER(pop3_debug_client_commands) "",
+	MEMBER(imap_debug_client_commands) "",
 	MEMBER(mail_full_filesystem_access) FALSE,
 	MEMBER(mail_max_keyword_length) 50,
 	MEMBER(mail_save_crlf) FALSE,
diff -ur dovecot-1.0.5/src/master/master-settings.h dovecot-1.0.5-debugcmd/src/master/master-settings.h
--- dovecot-1.0.5/src/master/master-settings.h	2007-07-16 07:51:07.000000000 +1200
+++ dovecot-1.0.5-debugcmd/src/master/master-settings.h	2007-10-11 11:54:22.000000000 +1300
@@ -74,6 +74,8 @@
 	unsigned int mail_cache_min_mail_count;
 	unsigned int mailbox_idle_check_interval;
 	bool mail_debug;
+	const char *pop3_debug_client_commands;
+	const char *imap_debug_client_commands;
 	bool mail_full_filesystem_access;
 	unsigned int mail_max_keyword_length;
 	bool mail_save_crlf;
diff -ur dovecot-1.0.5/src/pop3/client.c dovecot-1.0.5-debugcmd/src/pop3/client.c
--- dovecot-1.0.5/src/pop3/client.c	2007-08-25 04:58:50.000000000 +1200
+++ dovecot-1.0.5-debugcmd/src/pop3/client.c	2007-10-11 11:54:22.000000000 +1300
@@ -385,6 +385,10 @@
 		return;
 	}
 
+	pop3_debug_client_commands_arr = NULL;
+	if (getenv("POP3_DEBUG_CLIENT_COMMANDS") != NULL)
+		pop3_debug_client_commands_arr = t_strsplit_spaces(getenv("POP3_DEBUG_CLIENT_COMMANDS"), ", ");
+
 	o_stream_cork(client->output);
 	while (!client->output->closed &&
 	       (line = i_stream_next_line(client->input)) != NULL) {
diff -ur dovecot-1.0.5/src/pop3/commands.c dovecot-1.0.5-debugcmd/src/pop3/commands.c
--- dovecot-1.0.5/src/pop3/commands.c	2007-05-19 23:14:04.000000000 +1200
+++ dovecot-1.0.5-debugcmd/src/pop3/commands.c	2007-10-11 11:54:22.000000000 +1300
@@ -668,11 +668,22 @@
 int client_command_execute(struct client *client,
 			   const char *name, const char *args)
 {
+	int i;
+
 	/* keep the command uppercased */
 	name = t_str_ucase(name);
 
 	while (*args == ' ') args++;
 
+	if (pop3_debug_client_commands_arr != NULL) {
+		for (i = 0; pop3_debug_client_commands_arr[i] != NULL; i++) {
+			if (strcasecmp(name, pop3_debug_client_commands_arr[i]) == 0) {
+				i_info("Client command: %s %s", name, args);
+				break;
+			}
+		}
+	}
+
 	switch (*name) {
 	case 'C':
 		if (strcmp(name, "CAPA") == 0)
diff -ur dovecot-1.0.5/src/pop3/common.h dovecot-1.0.5-debugcmd/src/pop3/common.h
--- dovecot-1.0.5/src/pop3/common.h	2007-05-19 23:14:04.000000000 +1200
+++ dovecot-1.0.5-debugcmd/src/pop3/common.h	2007-10-11 11:54:22.000000000 +1300
@@ -21,6 +21,7 @@
 extern bool enable_last_command, no_flag_updates, reuse_xuidl, lock_session;
 extern const char *uidl_format, *logout_format;
 extern enum uidl_keys uidl_keymask;
+extern char **pop3_debug_client_commands_arr;
 
 extern void (*hook_mail_storage_created)(struct mail_storage *storage);
 extern void (*hook_client_created)(struct client **client);
diff -ur dovecot-1.0.5/src/pop3/main.c dovecot-1.0.5-debugcmd/src/pop3/main.c
--- dovecot-1.0.5/src/pop3/main.c	2007-07-16 07:58:50.000000000 +1200
+++ dovecot-1.0.5-debugcmd/src/pop3/main.c	2007-10-11 11:54:22.000000000 +1300
@@ -48,6 +48,7 @@
 bool lock_session = FALSE;
 const char *uidl_format, *logout_format;
 enum uidl_keys uidl_keymask;
+char **pop3_debug_client_commands_arr;
 
 static void sig_die(int signo, void *context __attr_unused__)
 {