Align README, docker-compose, .env.template with SMTP mailer

Replace all Postmark references (POSTMARK_API_KEY, POSTMARK_SENDER_ADDRESS)
with SMTP configuration (SMTP_HOST, SMTP_PORT, SMTP_USER, SMTP_PASSWORD,
SMTP_FROM) across documentation, deployment config, template, and test.

- README.md: architecture diagram (Postmark → SMTP) and configuration table
- docker-compose.yml: POSTMARK_* env vars replaced with SMTP_* required vars
- .env.template: POSTMARK_* entries replaced with SMTP_* entries
- test/integration.sh: POSTMARK_* test exports replaced with SMTP_* test values

.env.template

@@ -5,7 +5,10 @@ BASE_URL=http://localhost:4738
 INDEXER_RELAYS=purplepag.es,relay.damus.io,relay.nostr.band
 DEFAULT_RELAYS=relay.damus.io,nos.lol
 SEARCH_RELAYS=relay.nostr.band
-POSTMARK_API_KEY=
-POSTMARK_SENDER_ADDRESS=
+SMTP_HOST=
+SMTP_PORT=
+SMTP_USER=
+SMTP_PASSWORD=
+SMTP_FROM=
 PORT=4738
 DATA_DIR=./data

README.md

@@ -19,7 +19,7 @@ Flotilla ──HTTP──▶ Mailship (POST /subscription/email)
                            UUID in path      ├── fetch event from relay
                            is the auth       ├── store in SQLite (dedup)
                                              │
-                                        cron fires ──▶ render digest ──▶ Postmark ──▶ email
+                                        cron fires ──▶ render digest ──▶ SMTP ──▶ email
 ```
 
 ## Configuration
@@ -30,8 +30,11 @@ Flotilla ──HTTP──▶ Mailship (POST /subscription/email)
 | `MAILSHIP_NAME` | ✓ | Name of this Mailship instance |
 | `MAILSHIP_URL` | ✓ | Public URL of this instance |
 | `BASE_URL` | ✓ | Base URL for callback URLs (same as MAILSHIP_URL typically) |
-| `POSTMARK_API_KEY` | ✓ | Postmark API key for sending emails |
-| `POSTMARK_SENDER_ADDRESS` | ✓ | Verified sender email in Postmark |
+| `SMTP_HOST` | ✓ | SMTP server hostname |
+| `SMTP_PORT` | ✓ | SMTP server port |
+| `SMTP_USER` | ✓ | SMTP username |
+| `SMTP_PASSWORD` | ✓ | SMTP password |
+| `SMTP_FROM` | ✓ | From email address for outgoing mail |
 | `DEFAULT_RELAYS` | ✓ | Comma-separated list of default relays |
 | `INDEXER_RELAYS` | ✓ | Comma-separated list of indexer relays |
 | `SEARCH_RELAYS` | ✓ | Comma-separated list of search relays |

docker-compose.yml

@@ -10,8 +10,11 @@ services:
       - MAILSHIP_NAME=${MAILSHIP_NAME:-Mailship}
       - MAILSHIP_URL=${MAILSHIP_URL:?required}
       - BASE_URL=${BASE_URL:?required}
-      - POSTMARK_API_KEY=${POSTMARK_API_KEY:?required}
-      - POSTMARK_SENDER_ADDRESS=${POSTMARK_SENDER_ADDRESS:?required}
+      - SMTP_HOST=${SMTP_HOST:?required}
+      - SMTP_PORT=${SMTP_PORT:?required}
+      - SMTP_USER=${SMTP_USER:?required}
+      - SMTP_PASSWORD=${SMTP_PASSWORD:?required}
+      - SMTP_FROM=${SMTP_FROM:?required}
       - DEFAULT_RELAYS=${DEFAULT_RELAYS:-wss://relay.damus.io,wss://relay.primal.net}
       - INDEXER_RELAYS=${INDEXER_RELAYS:-wss://purplepag.es,wss://relay.damus.io}
       - SEARCH_RELAYS=${SEARCH_RELAYS:-wss://relay.nostr.band}

test/integration.sh

@@ -46,8 +46,11 @@ export MAILSHIP_SECRET="$SECRET"
 export MAILSHIP_NAME="Mailship Test"
 export MAILSHIP_URL="$BASE_URL"
 export BASE_URL="$BASE_URL"
-export POSTMARK_API_KEY="test"
-export POSTMARK_SENDER_ADDRESS="test@test.com"
+export SMTP_HOST="localhost"
+export SMTP_PORT="587"
+export SMTP_USER="test@test.com"
+export SMTP_PASSWORD="test"
+export SMTP_FROM="test@test.com"
 export DEFAULT_RELAYS="wss://relay.damus.io"
 export INDEXER_RELAYS="wss://purplepag.es"
 export SEARCH_RELAYS="wss://relay.nostr.band"