Thank you for reaching out to the Community. I can understand how helpful it is to use our Quicksend feature for over 500 contacts. The good news is this contact limit is under the reporting section of your campaigns. Adding these contacts into a newly created list, then using the Quicksend under your Contacts tab is a workaround we suggest.
We have even seen customers copy the campaign and send this copy to the new list.
I know about the workaround, but still then I need to create a copy of the email I sent and then send it to the new list I created. It is too many steps to do for re-sending an email to the people who did not open the first time. I request that we be allowed to quicksend to those who did not open the first time without a 500 contact limit.
I apologize for any confusion there may have been with my response. Once these contacts have been added to your new list, you do not have to copy your previously email and schedule this copied campaign. Being able to use our Quicksend feature to a list larger than 500 in your campaign's report is a feature request we have submitted in your account to the appropriate teams.