You can use a while loop with one second delay like this:

if ($nick isop #) && (!%antispam) {
    set -u7 %antispam $true
    msg # We currently have [#ofsponsors]
    var %i 1
    while %i <= 7 {
      .timer 1 %i msg # --> sponsor %i
      inc %i
  }
  }
  else {
    .notice $nick you not authorized to use this command 
  } 
 }

so you don't have to repeat msg # all the way from 1 to 7, along with several timers jotted down.