Mail is transferred with this protocol, which listens on TCP 25.
Also called Simple Mail Transfer Protocol.
In the Ultra Transcenders books
AZ-700SC-5002V0-17.25AB-900SC-200SC-300AZ-802
Each book explains SMTP in context, with comparison tables and the common traps.
Terms in this definition
- TCP
A transport protocol that is connection-oriented.
Related terms
- Duplicate attribute resiliency
If two objects claim the same UPN or SMTP proxy address, Microsoft Entra sync doesn't fail the export; it parks the clashing value and gives the object a stand-in onmicrosoft.com UPN. Once someone sorts out the clash, the original value returns without any manual step. This behaviour can't be switched off.
- Hard match
When syncing, an on-premises object is first paired with one already in the cloud using sourceAnchor and immutableId. Only when that pairing doesn't work does sync fall back to a soft match on UPN or primary SMTP address.
- SMTP connector
Connector for Logic Apps that sends email via an SMTP server you run yourself.
- Soft match
If matching on sourceAnchor fails and the cloud account lacks an immutableId, Microsoft Entra Connect tries to join an on-premises user to an existing cloud one using their primary SMTP address or userPrincipalName.