Well-known · Cross-platform

366 ODMR

TCP Yes
UDP
SCTP
DCCP

What it is

On-Demand Mail Relay.

When / why

Intermittently connected mail pickup.

Protocol status detail

TransportStatusMeaning
TCP Yes Assigned by IANA and standardized, specified, or widely used on this port.
UDP Not applicable for this transport.
SCTP Not applicable for this transport.
DCCP Not applicable for this transport.

Port range

Well-known (0–1023). System port for a core service. On Unix-like systems, binding it requires superuser privileges.

Browse all ports →

Firewall rules for port 366

Copy-ready inbound rules for the active transports. Replace every <source> placeholder with the specific host, subnet, or CIDR that should reach this port.

ufw

sudo ufw allow proto tcp from <source> to any port 366

Allow TCP 366 (ODMR). Replace <source> with the network/host that should reach it.

firewalld

sudo firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<source>" port port="366" protocol="tcp" accept'

Allow TCP 366 (ODMR) from <source>. Run 'firewall-cmd --reload' afterwards.

nftables

nft add rule inet filter input ip saddr <source> tcp dport 366 accept

Allow TCP 366 (ODMR). Assumes table 'inet filter' with an 'input' chain.

iptables

sudo iptables -A INPUT -p tcp -s <source> --dport 366 -j ACCEPT

Allow TCP 366 (ODMR). Persist with iptables-save/netfilter-persistent.

Azure NSG

az network nsg rule create -g <resource-group> --nsg-name <nsg> -n Allow-odmr-366 --priority 1000 --access Allow --direction Inbound --protocol TCP --source-address-prefixes <source> --destination-port-ranges 366

Inbound rule for 366 (ODMR). Set <source> to a CIDR; lower priority number = higher precedence.

AWS Security Group

aws ec2 authorize-security-group-ingress --group-id <sg-id> --ip-permissions IpProtocol=tcp,FromPort=366,ToPort=366,IpRanges="[{CidrIp=<source-cidr>}]"

Inbound TCP 366 (ODMR). Replace <source-cidr> (e.g. 10.0.0.0/16).

GCP firewall

gcloud compute firewall-rules create allow-odmr-366 --direction=INGRESS --action=ALLOW --rules=tcp:366 --source-ranges=<source-cidr> --network=<network>

Ingress rule for 366 (ODMR). Scope with --source-ranges and optionally --target-tags.

Windows netsh

netsh advfirewall firewall add rule name="Allow ODMR 366/TCP" dir=in action=allow protocol=TCP localport=366 remoteip=<source>

Inbound TCP 366 (ODMR). Set remoteip to a host/subnet; 'any' is discouraged.

Windows PowerShell

New-NetFirewallRule -DisplayName "Allow ODMR 366/TCP" -Direction Inbound -Action Allow -Protocol TCP -LocalPort 366 -RemoteAddress <source>

Inbound TCP 366 (ODMR). Replace <source> with a host or subnet.

Rules are generated only for transports marked active for this port. They default to an inbound allow with an explicit source placeholder — never any. Review direction, scope, and rule precedence before applying in production.