Well-known · Cross-platform

465 SMTPS (submission)

TCP Yes
UDP No
SCTP —
DCCP —

What it is

Message submission over implicit TLS (RFC 8314 preferred submission port).

When / why

Mail clients submitting authenticated mail over TLS. Preferred over 587/STARTTLS.

Protocol status detail

TransportStatusMeaning
TCP Yes Assigned by IANA and standardized, specified, or widely used on this port.
UDP No Not assigned, standardized, or widely used on this port.
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 465

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 465

Allow TCP 465 (SMTPS (submission)). 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="465" protocol="tcp" accept'

Allow TCP 465 (SMTPS (submission)) from <source>. Run 'firewall-cmd --reload' afterwards.

nftables

nft add rule inet filter input ip saddr <source> tcp dport 465 accept

Allow TCP 465 (SMTPS (submission)). Assumes table 'inet filter' with an 'input' chain.

iptables

sudo iptables -A INPUT -p tcp -s <source> --dport 465 -j ACCEPT

Allow TCP 465 (SMTPS (submission)). Persist with iptables-save/netfilter-persistent.

Azure NSG

az network nsg rule create -g <resource-group> --nsg-name <nsg> -n Allow-smtpssubmission-465 --priority 1000 --access Allow --direction Inbound --protocol TCP --source-address-prefixes <source> --destination-port-ranges 465

Inbound rule for 465 (SMTPS (submission)). 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=465,ToPort=465,IpRanges="[{CidrIp=<source-cidr>}]"

Inbound TCP 465 (SMTPS (submission)). Replace <source-cidr> (e.g. 10.0.0.0/16).

GCP firewall

gcloud compute firewall-rules create allow-smtpssubmission-465 --direction=INGRESS --action=ALLOW --rules=tcp:465 --source-ranges=<source-cidr> --network=<network>

Ingress rule for 465 (SMTPS (submission)). Scope with --source-ranges and optionally --target-tags.

Windows netsh

netsh advfirewall firewall add rule name="Allow SMTPS (submission) 465/TCP" dir=in action=allow protocol=TCP localport=465 remoteip=<source>

Inbound TCP 465 (SMTPS (submission)). Set remoteip to a host/subnet; 'any' is discouraged.

Windows PowerShell

New-NetFirewallRule -DisplayName "Allow SMTPS (submission) 465/TCP" -Direction Inbound -Action Allow -Protocol TCP -LocalPort 465 -RemoteAddress <source>

Inbound TCP 465 (SMTPS (submission)). 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.