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PMTA knowledge base›Mechanism§ 11.19.5.2

Mail merge via SMTP extensions

mailmerge SMTP extensions
The same merge without a binding

SMTP extensions used to submit a mail merge over an ordinary mail connection, without a binding.

Three commands: XMRG replaces MAIL FROM and keeps its extensions — DSN, VERP; XDFN sets variables for the recipient that follows, as name=value pairs; XPRT replaces DATA and transfers one part — with a number, and the last one marked LAST.

A part is transferred as with DATA: with dot escaping and a dot on a separate line at the end.

The main trap is forgetting LAST. Only the part with this mark completes the submission: without it the node waits for the next XPRT, and the message does not go out.
What the Hub does. Not used: warm-up messages are submitted over ordinary SMTP, one per recipient.
Recommended values

Three commands:

Command Replaces What it does
XMRG MAIL FROM sender and extensions
XDFN — variables for the next recipient
XPRT DATA one part; the last one with LAST
The three commands, their order and the last part’s mark come from the manual (§ 11.19.5.2). The table is ours.
Example configuration
XMRG FROM:<travelAlerts@example.port25.com> VERP
XDFN FName="Bob" *parts=1,3
RCPT TO:<bob@example.port25.com>
XPRT 1
A shortened example from the manual: after a part’s text comes a dot on a separate line; the last part is XPRT 3 LAST.
yellow — — directive names, blue — blocks. They are highlighted the same way in the text of the card.
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.
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Related entries

3 relations

Does not work without

allow-mailmerge<source>The directive that enables this mechanism. § 11.19.3

Works together with

Two attachment points — and two different behaviorsA related mechanism: they work together. § 11.15.1

Where you can see it

Personalization inside the engineA related mechanism: they work together. § 11.19.5.2

Referenced from

Submitting a message by writing a file into a directoryHere merging is set not by protocol commands but by the file format. § 11.19.5.3

How to check on the node
Check whether mail merge is allowed for the source:
grep -rn 'allow-mailmerge' /etc/pmta/
Merge commands are accepted only from a source with allow-mailmerge.
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What else to read

3 articles

◇Personalization inside the engineVariables are set per recipient, and the node substitutes them at delivery — one submitted message goes to many recipients with different content.◇How a message gets into the engineSix described submission methods: extended SMTP, four language bindings and a directory the node watches on disk.◇Who is allowed to submit mail and for whom to accept itOut of the box, the node accepts submission only from the machine itself; two different questions — “who can send through us” and “for whose addresses we accept mail” — are answered by different directives.

In the Hub
Cost of a mistake
reversible: harms only while it is set
Scenarios
Address warm-up · Connect a sending platform