1) at the moment my "leads" list has some 1.500 names, to whom I have just send a mail doing what is called, if I am not wrong, "mass @mailing". One question is:

a) considering that at my account level there's a limit of 500 mails sent daily, how may I know who, amongst all of the 1.500, has been sent my @mail and, therefore, who's not?

b) my former question seems to be only "academic", by the way, 'cause the system did not permit me to send any @mail, not even one to myself to see what my leads are supposed to receive, stating "Invio dei messaggi non riuscito! Spiacenti, si è superato il limite di 500 @mail al giorno in questa versione" (Message sending failed! Sorry, you have exceeded the limit of 500 mail day in this version)   .. but I did not send any one, how is this possibile?

awaiting for your kind assistance please accept my best regards