The size of the message you are trying to send exceeds a temporary size limit of the server. The message was not sent; try to reduce the message size or wait some time and try again. The server responded: 4.5.3 Error: too many recipients.
We set this in main.cf:
We didn't specify it before and the default is said to be 0/unlimited and it still didn't change anything.........
That is pinging to the gateway IP on the same switch, the same IP is pingable externally without any problems which makes me think the switch is fine.
64 bytes from 184.108.40.206: icmp_seq=4 ttl=255 time=1.07 ms
64 bytes from 220.127.116.11: icmp_seq=1 ttl=255 time=3536 ms
64 bytes from 18.104.22.168: icmp_seq=2 ttl=255 time=2536 ms
64 bytes from 22.214.171.124: icmp_seq=3 ttl=255 time=1536 ms
64 bytes from 126.96.36.199: icmp_seq=8 ttl=255 time=1.20 ms