You can add up to 40 recipients.
Note: Avoid using many peer connections, if possible. The default delivery queue buffer for each peer (
Max Queue Length) is 50 MB. Based on the default setting, to enable 20 peers, 20 * 50 MB = 1 GB of process memory for delivery buffers is required. If you use 40 peers, 2 GB of process memory is required, exceeding the 32-bit process memory limit.
If you want to use that many peers, then you must reduce the default delivery queue memory to 25 MB, keeping the total queue memory usage to 1 GB.