An unsupported mailer URL now gives a more specific error than EINVAL.

@@ -58,10 +58,11 @@ extern "C" {
 #define MU_ERR_MAILER_BAD_FROM      (MU_ERR_BASE | 0x013)
 #define MU_ERR_MAILER_BAD_TO        (MU_ERR_BASE | 0x014)
 #define MU_ERR_MAILER_NO_RCPT_TO    (MU_ERR_BASE | 0x015)
-#define MU_ERR_SMTP_RCPT_FAILED     (MU_ERR_BASE | 0x016)
+#define MU_ERR_MAILER_BAD_URL       (MU_ERR_BASE | 0x016)
+#define MU_ERR_SMTP_RCPT_FAILED     (MU_ERR_BASE | 0x017)
 
-#define MU_ERR_TCP_NO_HOST          (MU_ERR_BASE | 0x017)
-#define MU_ERR_TCP_NO_PORT          (MU_ERR_BASE | 0x018)
+#define MU_ERR_TCP_NO_HOST          (MU_ERR_BASE | 0x018)
+#define MU_ERR_TCP_NO_PORT          (MU_ERR_BASE | 0x019)
 
 const char* mu_errname __P((int e));
 const char* mu_errstring __P((int e));

@@ -70,6 +70,7 @@ mu_errname (int e)
     EN(MU_ERR_BAD_RESUMPTION)
     EN(MU_ERR_MAILER_BAD_FROM)
     EN(MU_ERR_MAILER_BAD_TO)
+    EN(MU_ERR_MAILER_BAD_URL)
     EN(MU_ERR_MAILER_NO_RCPT_TO)
     EN(MU_ERR_SMTP_RCPT_FAILED)
     EN(MU_ERR_TCP_NO_HOST)
@@ -113,6 +114,7 @@ const char* mu_errstring (int e)
     ES(MU_ERR_MAILER_BAD_FROM,  "Not a valid mailer from address")
     ES(MU_ERR_MAILER_BAD_TO,    "Not a valid mailer to address")
     ES(MU_ERR_MAILER_NO_RCPT_TO,"No receipt addresses found")
+    ES(MU_ERR_MAILER_BAD_URL,   "Malformed or unsupported mailer URL")
     ES(MU_ERR_SMTP_RCPT_FAILED, "SMTP rcpt to command failed")
     ES(MU_ERR_TCP_NO_HOST,      "Tcp connections need a host")
     ES(MU_ERR_TCP_NO_PORT,      "Tcp connections need a postive port")