Craigslist emails

Already can collect email the addresses. I have seen several people request similar on here before. Just want the most efficient method to send emails such as: sale-gmvhj-xxxxx@craigslist.org. I want to automate as much as possible & send the most emails possible from the fewest amount of email accounts. For sending normal emails, I already have automated using excel & Outlook so a method using those would be preferred, but not at all required. My marketing is targeted, however, I do not know the exact limitations craigslist allows per account/per day etc. Thank you. I just want to reiterate, I ALREADY have built a tool that uses excel & Outlook. I am only looking for help regarding the "craigslist" related email addresses. Thank you.