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PMTA knowledge base›Block Global›Directive§ 11.2.2.1

enable-inline-seeding

Global

Enable automatic seeding and name the subaccount
in the configuration this is a lineenable-inline-seeding true at global scope when the configuration block exists, otherwise falseinside the block Global
Three scopes, two subtleties and two warnings

The default depends on the configuration: at the node level it is true if the <inline-seeding> block is declared, and false if not.

The line works in three scopes: the node, a pool of sending addresses, an individual sending address. Inheritance is the usual one: an address takes the value from both the pool and the node, and the pool takes precedence.

The value can carry a subaccount number — true,subaccount=N. And here is a subtlety the manual names directly: true without a subaccount does not inherit the subaccount from the level above but resets it. To inherit, the line is not written at all.

Two vendor warnings separately. A signing key in the message header is not fully supported: seed messages may go out unsigned or signed with a different key. And sending domains not in Latin script are not fully supported either.

The mechanism itself is described in inline-seeding.

The main trap is that true resets the subaccount rather than inheriting it. The behavior looks like a typo until you read it: a true line at the sending address level with a subaccount set at the node level means “no subaccount,” not “take it from above.”

The rule is simple and counterintuitive: to inherit, do not write the line. Once you write it, you have to repeat the subaccount too.

The other half: the neighboring event upload line, enable-signals, works the same way. It is easy to make the mistake twice, and both mistakes are silent.

What the Hub does. It does not write it: we do not use the vendor’s seeding, there is no <inline-seeding> block in the configuration — so the default here is false.

The task the mechanism solves is postponed for us: seed mailboxes require IMAP polling, and polling from one address ends with the mailboxes being blocked. Hence the postponed decision about a proxy.

Recommended values

What to set. A choice of three, and the middle one is a trap:

Value When
do not write it the value from above must be inherited together with the subaccount
true,subaccount=N this level works with its own subaccount
false seeding is off here

A plain true is a fourth option, and it means “enabled, no subaccount.” That is rarely what was intended: if a subaccount is set above, it will be lost.

The three scopes, the inheritance rule with pool precedence, the subaccount reset by the value true and both warnings (the signing key in the header, domains not in Latin script) come from the manual, § 11.2.2.1. The default depending on the presence of the block comes from there too.
Example configuration
# to inherit the subaccount, the line is not written at all
<virtual-mta shop-example-com>
    enable-inline-seeding true,subaccount=123</virtual-mta>
Without the subaccount part the same line would mean “enabled, no subaccount” — and would reset the number set at the node or pool level.
yellow — — directive names, blue — blocks. They are highlighted the same way in the text of the card.
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Common mistakes and problems

what people get wrong and how it ends3 mistakes▶

Writing true expecting to inherit the subaccount

§ 11.2.2.1

What it costsA value without the subaccount part means “no subaccount.” The number set at the node or pool level is reset, and seed events go to the wrong place.
How to spot itIn the service’s reports, seeding is attributed to the main account rather than the subaccount.
How to do it rightEither do not write the line at all — then everything is inherited — or repeat the subaccount explicitly.

Relying on a signing key from the message header

§ 11.2.2.1

What it costsThe manual says this method is not fully supported: seed messages may go out unsigned or signed with a different key — for example, one with a wildcard domain.
How to spot itSeed messages arrive without a signature or with someone else’s selector.
How to do it rightDeclare signing keys in the configuration rather than passing them in a header.

Expecting inheritance from the node after setting a value on the pool

§ 11.2.2.1

What it costsThe pool takes precedence over the node. A value set on the pool overrides the general one, and the addresses of that pool never learn about the node’s setting.
How to spot itSome sending addresses behave differently from what is set at the node level.
How to do it rightLook at all three scopes at once: the address, its pool and the node.
Compatibility
PowerMTA 6.0
described in the manual of this version · platform: any
The vendor does not state the first version for every directive — there is no note here. The name also appears in the 5.0 edition of the manual.
Reference data
Syntax
enable-inline-seeding { true | false } [subaccount N]
Values
true[,subaccount=N] | false
Default
true at global scope when the configuration block exists, otherwise false § 11.2.2.1
Applying
a service restart is required
Queue
also affects what is already in the queue
Where to write it
Global, <virtual-mta-pool>, <virtual-mta>
How many times
once in the block
Everything here comes from the manual, with the section.
Inheritance
The directive applies in three scopes: the node, a pool of sending addresses and an individual address. An address inherits from both, and the pool takes precedence over the node. But inheritance breaks if you write true without a subaccount: then the subaccount is reset rather than taken from above.
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Related directives

2 relations

Works together with

enable-signalsGlobalA neighboring line with the same design — and the same trap: the value true without a subaccount resets it. § 11.2.1

Where you can see it

Seeding campaigns with control addressesHow the whole mechanism works: what gets seeded, under what conditions and what it costs. § 11.2.2.1

How to check on the node
You need to look at all three scopes at once — the value is made up of them:
grep -n 'enable-inline-seeding\|^<inline-seeding>' /etc/pmta/config /etc/pmta/virtualhost.txt
The absence of lines means the default based on the presence of the seeding block: a block is there — enabled, no block — disabled. A true line without a subaccount at any level resets the number set above.
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What else to read

2 articles

◇Seeding campaigns with control addressesThe engine mixes the vendor’s addresses into a mailing, and the result is viewed in the vendor’s deliverability tool; independent of event export.◇Job headerThe x-job header tags a message with a job; the node reads it only if the source is allowed process-x-job, and then the job is visible in accounting, the monitor and pause commands.

In the Hub
Cost of a mistake
reversible: harms only while it is set
Scenarios
Seeding and seed mailboxes
Neighboring settings of the block Global:enable-signalssmtp-proxy-source-hosthost-namepostmasterdomain-keyAll 108 directives of the block →