Fix problem of testing email server with existing parameters.

In existing email parameters the password consists only of asterisks.
In that case, get the password from storage.
Also improve the logging of failed authentication attempts.

sabnzbd/emailer.py

@@ -55,6 +55,9 @@ def send(message, email_to, test=None):
         email_from    = test.get('email_from')
         email_account = test.get('email_account')
         email_pwd     = test.get('email_pwd')
+        if email_pwd and not email_pwd.replace('*', ''):
+            # If all stars, get stored password instead
+            email_pwd = cfg.email_pwd()
     else:
         email_server  = cfg.email_server()
         email_from    = cfg.email_from()
@@ -113,8 +116,14 @@ def send(message, email_to, test=None):
         if (email_account != "") and (email_pwd != ""):
             try:
                 mailconn.login(email_account, email_pwd)
+            except smtplib.SMTPHeloError:
+                return errormsg(T("The server didn't reply properly to the helo greeting"))
+            except smtplib.SMTPAuthenticationError:
+                return errormsg(T("Failed to authenticate to mail server"))
+            except smtplib.SMTPException:
+                return errormsg(T("No suitable authentication method was found"))
             except:
-                return errormsg(T('Failed to authenticate to mail server'))
+                return errormsg(T("Unknown authentication failure in mail server"))
 
         try:
             mailconn.sendmail(email_from, email_to, message)