Hi..
Feature request DNS server for forwarder custom port can be like this ? servers: 202.110.111.112:5353 / servers: 202.110.111.112:443
/ip dns> print
servers: 202.110.111.111:5353
dynamic-servers:
allow-remote-requests: yes
max-udp-packet-size: 4096
query-server-timeout: 2s
query-total-timeout: 10s
cache-size: 2048KiB
cache-max-ttl: 1w
cache-used: 14KiB

so many isp redirect / transparent udp port 53 to their dns, this can be mail server can’t resolve the dns request and rejected all incoming email (wrong answering ptr, txt record and etc)
Thank a lot