While qualifying eMail for Spam, Hotmail/Live checks the historical records of numbers of eMails sent by a sender (FROM, eMail Server, IP, etc.). Some times, perfectly valid bulk eMails that are not Spam, (i.e. double opt-in list, from a server with proper SPF Record, signed with DKIM, unregister links and contact info, etc.) are rejected and not delivered to destinataries. Not even to their Junk folder. I guess we can avoid this situation by progressivelly "training" Hotmail/Live about the reputation of our sender and sending small quantyties of eMails innitially and increasing the quantity for some amount/percentaje during each delivery. Are there guidelines or do you have any experience on these quantities, strategy, solutions? Thank you in advance. EDIT: This question with a bounty is still unanswered. 8 hours to be automatically awarded! Do you have the answer?