Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 306540)
+++ channels/chan_sip.c	(working copy)
@@ -20894,20 +20894,93 @@
 		/* Confirm that we received this packet */
 		transmit_response(p, "200 OK", req);
 	} else if (!strcmp(event, "message-summary")) {
-		const char *mailbox = NULL;
+		const char *mailbox = NULL; 
 		char *c = ast_strdupa(get_body(req, "Voice-Message", ':'));
+		char *context = "SIP_Remote";
 
 		if (!p->mwi) {
-			struct sip_peer *peer = find_peer(NULL, &p->recv, TRUE, FINDPEERS, FALSE, p->socket.type);
+			ast_debug(4, "Unsolicited MWI received from: %s\n", ast_sockaddr_stringify(&p->recv));
+			/* note: If you intend to light unsolicited MWI lights on your phones, 
+				they must be in the same context as the unsolicited_mailbox parameter in the format of:
+				default_box@context */
 
+			struct sip_peer *peer = find_peer(NULL, &p->recv, TRUE, FINDPEERS, FALSE, p->socket.type); 
+
 			if (peer) {
-				mailbox = ast_strdupa(peer->unsolicited_mailbox);
+				char *unsolicited_mailbox = ast_strdupa(peer->unsolicited_mailbox);
+				if(!unsolicited_mailbox || ast_strlen_zero(unsolicited_mailbox)) {
+					 ast_debug(2, "unsolicited_mailbox was not set for peer %s, unsolicited MWI will not be delivered.\n", ast_sockaddr_stringify(&p->recv));
+				}
+				else {
+					{
+						char* mailbox_only = strchr(unsolicited_mailbox, '@');
+						if (mailbox_only) {
+							*mailbox_only = '\0';
+						}
+					}
+
+					/* If the unsolicited_mailbox parameter has an @ symbol, use that for the context, otherwise leave it at the default of SIP_Remote. */
+					char *unsolicited_context = ast_strdupa(peer->unsolicited_mailbox);
+					if(unsolicited_context) {
+						unsolicited_context = strchr(unsolicited_context, '@');
+						if(unsolicited_context) {
+							unsolicited_context++;
+						}
+						if(unsolicited_context && !ast_strlen_zero(unsolicited_context)) {
+							context = unsolicited_context;
+						}
+					}
+					//If the user has specfied a mailbox to send *all* unsolicited messages to, send them directly there.
+					if(unsolicited_mailbox && !ast_strlen_zero(unsolicited_mailbox)) {
+						mailbox = unsolicited_mailbox;	
+					}
+					else
+					{
+						/* RFC3842 (For the Message-Account header) states: 
+							If the Request-URI or To header in a message-summary subscription
+							corresponds to a group or collection of individual messaging
+							accounts, the notifier MUST specify to which account the message-
+							summary body corresponds.
+		
+							Therefore, use Message-Account from the body first, and then failback to the To header.
+						*/
+						char *specified_extension = ast_strdupa(get_body(req, "Message-Account", ':'));
+						if(!specified_extension || ast_strlen_zero(specified_extension)) {
+							specified_extension = ast_strdupa(get_header(req, "To"));
+						}
+	
+						if(specified_extension && !ast_strlen_zero(specified_extension)) {
+							/* Get the mailbox from the format: <sip:mailbox@ipaddress:port> */
+							char *specified_mailbox = strchr(specified_extension, '@');
+							if (specified_mailbox) {
+								*specified_mailbox = '\0';
+							}
+							specified_mailbox = strchr(specified_extension, ':');
+							if (specified_mailbox) {
+								specified_mailbox++;
+		
+								if(specified_mailbox && !ast_strlen_zero(specified_mailbox)) {
+									mailbox = specified_mailbox;
+								}
+							}
+						}
+					}
+					if(mailbox && !ast_strlen_zero(mailbox))
+						ast_debug(4, "Unsolicited MWI being delivered to: %s@%s\n", mailbox, context);
+					else
+						ast_debug(2, "Could not find a valid mailbox. Unsolicited MWI will not be delivered.");
+				}
+				
 				unref_peer(peer, "removing unsolicited mwi ref");
 			}
+			else {
+				ast_debug(2, "Unsolicited MWI received from an unknown peer and wont be routed: %s\n", ast_sockaddr_stringify(&p->recv));
+			}
 		} else {
 			mailbox = p->mwi->mailbox;
 		}
 
+
 		if (!ast_strlen_zero(mailbox) && !ast_strlen_zero(c)) {
 			char *old = strsep(&c, " ");
 			char *new = strsep(&old, "/");
@@ -20915,7 +20988,7 @@
 
 			if ((event = ast_event_new(AST_EVENT_MWI,
 						   AST_EVENT_IE_MAILBOX, AST_EVENT_IE_PLTYPE_STR, mailbox,
-						   AST_EVENT_IE_CONTEXT, AST_EVENT_IE_PLTYPE_STR, "SIP_Remote",
+						   AST_EVENT_IE_CONTEXT, AST_EVENT_IE_PLTYPE_STR, context,
 						   AST_EVENT_IE_NEWMSGS, AST_EVENT_IE_PLTYPE_UINT, atoi(new),
 						   AST_EVENT_IE_OLDMSGS, AST_EVENT_IE_PLTYPE_UINT, atoi(old),
 						   AST_EVENT_IE_END))) {
Index: configs/sip.conf.sample
===================================================================
--- configs/sip.conf.sample	(revision 306540)
+++ configs/sip.conf.sample	(working copy)
@@ -1092,7 +1092,15 @@
 ;                       ; same location).
 ; directmediapermit
 ; directmediadeny
-; unsolicited_mailbox
+; unsolicited_mailbox ; is to specify a mailbox and or context to deliver unsolicited 
+					  ; sip notify / MWI messages to in the format of box@context.
+					  ; If a box is specified, all unsolicited notifies will be delivered 
+					  ; to that box.
+					  ; If a context is specified, unsolicited messages will be delivered 
+					  ; in that context. (Otherwise SIP_Remote is the default context).
+					  ; If no box is specified (IE: unsolicied_mailbox=@default)
+					  ; unsolicited messages will be delivered to the box specified in
+					  ; the SIP notify at the context specified.
 ; use_q850_reason
 ; maxforwards
 ; encryption