guess From address from Received headers

[notmuch] / notmuch-reply.c

diff --git a/notmuch-reply.c b/notmuch-reply.c
index 6c15536cff153d3d00ebe4d8a300c6361a9ea536..3c5b253e0c15ad99a3dd6e8a8636464536f9c78c 100644 (file)
--- a/notmuch-reply.c
+++ b/notmuch-reply.c
@@ -282,6 +282,69 @@ add_recipients_from_message (GMimeMessage *reply,
     return from_addr;
 }
 
+
+static const char *
+guess_from_received_header(notmuch_config_t *config, notmuch_message_t *message)
+{
+    const char *received,*primary;
+    char **other;
+    char *by,*mta,*ptr,*token;
+    char *domain=NULL;
+    char *tld=NULL;
+    const char *delim=". \t";
+    size_t i,other_len;
+
+    received = notmuch_message_get_header (message, "received");
+    by = strstr(received," by ");
+    if (by && *(by+4)) {
+       /* we know that there are 4 characters after by - either the 4th one
+        * is '\0' (broken header) or it is the first letter of the hostname 
+        * that last received this email - which we'll use to guess the right
+        * from email address
+        */
+       mta = strdup(by+4);
+       if (mta == NULL)
+           return NULL;
+       /* After the MTA comes its IP address (or HELO response) in parenthesis.
+        * so let's terminate the string there
+        */
+       if ((ptr = strchr(mta,'(')) == NULL) {
+           free (mta);
+           return NULL;
+       }
+       *ptr = '\0';
+       /* Now extract the last two components of the MTA host name
+        * as domain and tld
+        */
+       token = mta;
+       while ((ptr = strsep(&token,delim)) != NULL) {
+           if (*ptr == '\0')
+               continue;
+           domain = tld;
+           tld = ptr;
+       }
+       if (domain) {
+           /* recombine domain and tld and look for it among the configured
+            * email addresses
+            */
+           *(tld-1) = '.';
+           primary = notmuch_config_get_user_primary_email (config);
+           if (strcasestr (primary, domain)) {
+               free(mta);
+               return primary;
+           }
+           other = notmuch_config_get_user_other_email (config, &other_len);
+           for (i = 0; i < other_len; i++)
+               if (strcasestr (other[i], domain)) {
+                   free(mta);
+                   return other[i];
+               }
+       }
+       free(mta);
+    }
+    return NULL;
+}
+
 static int
 notmuch_reply_format_default(void *ctx, notmuch_config_t *config, notmuch_query_t *query)
 {
@@ -312,9 +375,13 @@ notmuch_reply_format_default(void *ctx, notmuch_config_t *config, notmuch_query_
        g_mime_message_set_subject (reply, subject);
 
        from_addr = add_recipients_from_message (reply, config, message);
-
-       if (from_addr == NULL)
-           from_addr = notmuch_config_get_user_primary_email (config);
+       
+       if (from_addr == NULL) {
+           from_addr = guess_from_received_header (config, message);
+           if (from_addr == NULL) {
+               from_addr = notmuch_config_get_user_primary_email (config);
+           }
+       }
 
        from_addr = talloc_asprintf (ctx, "%s <%s>",
                                     notmuch_config_get_user_name (config),