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IT Atlas

Protocol

SMTP

Server to server mail transfer

Port 25TCPEncrypted: Optional

Record

Ports
25
Transport
TCP
Encryption
Optional
Typical use
Inbound mail delivery, relays

Security considerations

Require STARTTLS; never operate an open relay

Where this protocol is explained

Exchange Online

Microsoft's cloud email service, including transport rules, connectors, mailbox permissions and hybrid coexistence with on premises Exchange.

Topics that use this protocol

Exchange Online

Microsoft's cloud email service, including transport rules, connectors, mailbox permissions and hybrid coexistence with on premises Exchange.

Other protocols over TCP

DNS over TLSFTPFTPSGlobal CatalogHTTPIMAP / IMAPSKubernetes APILDAPSMicrosoft SQL ServerMySQL / MariaDB

In the knowledge graph

Open the interactive map centred on this entity to see everything it connects to and travel outwards from there.

Explore SMTP in the knowledge graph