Postfix

Mail server logs

Global Fields (4)

FieldType
ngs.createdAt
Timestamp when the event was created locally.
pdate
ngs.id
Unique identifier for the log entry.
string
ngs.indexedAt
Timestamp when the log was indexed into the SIEM.
pdate
ngs.source
Origin or source system of the log.
string

Generic Fields (8)

These are common fields that appear across multiple namespaces. They represent attributes that are inherited or reused from a global schema— things like timestamps, unique identifiers, user IDs, or status codes that every namespace needs. By sharing these fields, we ensure consistency and make it easy to run cross-namespace searches and reports.

FieldReference-Specific FieldsType
gen.mail.sender
Email address of the message sender.
postfix.from
strings
gen.mail.receiver
Email address of the message recipient.
postfix.to
strings
gen.src.ip
Source IP address.
postfix.clientIp
text_general
gen.dest.ip
Destination IP address.
postfix.relayIp
postfix.serverIp
text_general
gen.dest.port
Destination port number.
postfix.relayPort
postfix.serverPort
pint
gen.src.port
Source port number.
postfix.clientPort
pint
gen.mail.size
Size of the email in bytes.
postfix.size
plong
gen.protocol
Network protocol used (e.g., TCP, UDP, ICMP).
postfix.proto
strings

Reference-Specific Fields (25)

FieldType
postfix.queueId
Unique identifier assigned by Postfix to the message in the mail queue.
string
postfix.messageId
Id of a Mail taken from the Message-ID header, for tracking the mail across mail systems
string
postfix.from
Envelope sender address of the email.
text_general
postfix.to
Envelope recipient address of the email.
text_general
postfix.clientHostname
Hostname of the SMTP client that connected to Postfix.
text_general
postfix.clientIp
IP address of the SMTP client that submitted the message.
text_general
postfix.status
Delivery status of the message (e.g., sent, deferred, bounced).
text_general
postfix.dsn
The Delivery Status Notification Code
string
postfix.dsnStatus
The main status of the Delivery Status Notification Code mapped according to iana
text_general
postfix.dsnSubStatus
Sub Status of the Delivery Status Notification Code mapped according to iana. In case no enumerated Status Code is available the subject sub-code will be used
text_general
postfix.details
Additional details of the event, such as error messages/reasons
text_general
postfix.delay
The Delay of the transaction in seconds
pfloat
postfix.relayIp
The IP of the Relay Server chosen to forward the mail to its final destination
string
postfix.relayHostname
The Hostname (if available) of the Relay Server chosen to forward the mail to its final destination
string
postfix.relayPort
The Port of the Relay Server chosen to forward the mail to its final destination
pint
postfix.clientPort
The Port of the Client
pint
postfix.size
The Size of the Mail in Bytes
plong
postfix.nrcpt
Number of recipients
pint
postfix.uid
pint
postfix.proto
Mail Protocol used
string
postfix.helo
The Domain the client presented itself with
string
postfix.serverHostname
Hostname of the mail server if available
string
postfix.serverIp
IP of the mail server
string
postfix.serverPort
Port of the mail server
pint
postfix.sessionInfo
Key Value pairs of Session Details provided on disconnect
strings

Sample Log Event

Below is a representative JSON log entry showing key fields as they're emitted by the system. Depending on the context of the event, some fields may be omitted if they're not applicable.