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.