feat: send mailings over MailJet smtp in dedicated worker process

config/packages/mailer.yaml

@@ -1,3 +1,8 @@
 framework:
     mailer:
-        dsn: '%env(MAILER_DSN)%'
+        # "main" has to stay first: it is the transport every mail without an explicit
+        # X-Transport header goes out over, which is all of them apart from the teamer
+        # mailing. Reordering this quietly moves the whole application to Mailjet.
+        transports:
+            main: '%env(MAILER_DSN)%'
+            mailing: '%env(MAILING_MAILER_DSN)%'

config/packages/messenger.yaml

@@ -12,6 +12,29 @@ framework:
                 retry_strategy:
                     max_retries: 3
                     multiplier: 2
+            # Bulk teamer mailings, kept off "async" so that a mailing of several hundred
+            # recipients cannot delay a password reset. Its own cron worker consumes this
+            # queue and nothing else; the two never see each other's messages, because the
+            # doctrine transport filters on the queue_name column. See docs/operations.md
+            # for both cron entries.
+            #
+            # The retry delays are spelled out because the default is one second: with a
+            # multiplier alone, all three retries of a mail are spent within seconds, so a
+            # short hiccup at the mail provider would drop a whole mailing into "failed" at
+            # once - the very thing sending one message per recipient is meant to avoid.
+            # A minute, three and nine outlive any realistic blip and span several runs of
+            # a worker that only lives for a few minutes at a time.
+            mailing:
+                dsn: '%env(MESSENGER_TRANSPORT_DSN)%'
+                options:
+                    queue_name: mailing
+                    use_notify: true
+                    check_delayed_interval: 60000
+                retry_strategy:
+                    max_retries: 3
+                    delay: 60000
+                    multiplier: 3
+                    max_delay: 900000
             failed: 'doctrine://default?queue_name=failed'
             sync: 'sync://'
 
@@ -20,6 +43,9 @@ framework:
             Symfony\Component\Notifier\Message\ChatMessage: async
             Symfony\Component\Notifier\Message\SmsMessage: async
 
+            # only the fan-out, the mails it produces carry an X-Bus-Transport header
+            App\Message\SendTeamerMailing: mailing
+
             # Route your messages to the transports
             # 'App\Message\YourMessage': async
 
@@ -30,3 +56,13 @@ when@dev:
                 Symfony\Component\Mailer\Messenger\SendEmailMessage: sync
                 Symfony\Component\Notifier\Message\ChatMessage: sync
                 Symfony\Component\Notifier\Message\SmsMessage: sync
+                App\Message\SendTeamerMailing: sync
+
+when@test:
+    framework:
+        messenger:
+            routing:
+                Symfony\Component\Mailer\Messenger\SendEmailMessage: sync
+                Symfony\Component\Notifier\Message\ChatMessage: sync
+                Symfony\Component\Notifier\Message\SmsMessage: sync
+                App\Message\SendTeamerMailing: sync

config/packages/zenstruck_schedule.yaml

@@ -3,13 +3,13 @@ zenstruck_schedule:
 
   mailer:
     service: mailer
-    default_to: [email protected]
-    default_from: info@ep-reisen.de
+    default_to: [email protected]
+    default_from: team@ep-reisen.de
     subject_prefix: "[MyE&P-Team]"
 
   schedule_extensions:
     email_on_failure:
-      to: [email protected]
+      to: [email protected]
 
   tasks:
     - task: app:bpn-import

config/services.yaml

@@ -9,6 +9,13 @@ parameters:
 
     teamer_inactive_period: '-2 years'
 
+    # Messenger transport the mails of a teamer mailing are queued on. An X-Bus-Transport
+    # header wins over the routing in messenger.yaml (see SendersLocator::getSenders),
+    # so this is what keeps a mailing off the shared queue - and what has to be switched
+    # back to "sync" further down, or a mailing would need a running worker to arrive
+    # in dev and test while every other mail is sent right away.
+    mailing_bus_transport: 'mailing'
+
     # Dates (MM-DD) on which teamers must re-confirm their personal data.
     personal_data_check_deadlines:
         - '04-01'
@@ -51,6 +58,7 @@ services:
             $xmlExport: '@xml_export.storage'
             $xmlDump: '@xml_dump.storage'
             $teamerInactivePeriod: '%teamer_inactive_period%'
+            $mailingBusTransport: '%mailing_bus_transport%'
 
     App\:
         resource: '../src/'
@@ -243,3 +251,15 @@ services:
                 myep_oauth2_url_access_token: '%env(MYEP_OAUTH2_URL_ACCESS_TOKEN)%'
                 myep_oauth2_url_resource_owner_details: '%env(MYEP_OAUTH2_URL_RESOURCE_OWNER_DETAILS)%'
                 myep_oauth2_scopes: '%env(csv:MYEP_OAUTH2_SCOPES)%'
+
+# The mails of a mailing are sent right away here, like every other mail, instead of
+# waiting for a worker on the dedicated queue. The mailer transport is deliberately not
+# switched: a mailing still goes out over MAILING_MAILER_DSN, so the path being exercised
+# locally is the one that runs in production.
+when@dev:
+    parameters:
+        mailing_bus_transport: 'sync'
+
+when@test:
+    parameters:
+        mailing_bus_transport: 'sync'