A little service that queues your mails via rabbitmq and sends them to a configured smtp server.
- smtp settings are fully configurable
- configurable rabbitmq entities
- retry logic within rabbitmq
- callback queue
- easily scalable
- build complex mail messages with inline attachments and all that stuff
There are 3 main parts in here "queue", "retry-queue" and "callback-queue".
A consumer listening on "queue",
if a mail can be sent successfully a message will be written to the callback-queue with {"success" : true}.
If the message could not be sent it will be put into the retry-queue.
The retry-queue is special, it has a dead-letter-exchange which is this original queue again(!) and a message ttl configured.
When the ttl is reached it gets send to the configured dead letter exchange -> back to the original queue
A mail-json:
Complete example:
{
"mail": {
"subject": "huhu",
"htmlContent": "<html><body>A<br><img src=\"cid:fancyCid\"/></a><br>B</body></html>",
"plainTextContent": "content🙉",
"attachments": [
{
"base64Content": "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",
"mimeType": "image/png",
"name": "imageFileName.png",
"contentDisposition": "INLINE",
"contentId": "fancyCid"
},
{
"base64Content": "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",
"mimeType": "image/png",
"name": "additionalAttachmentFileName.png",
"contentDisposition": "ATTACHMENT"
}
]
},
"recipients": [
"fun@bla.de"
],
"from": "defaultfromaddress@fancydomain.de",
"cc": [],
"bcc": [],
"replyTo" : []
}Some notes about required fields and combinations
- subject is mandatory
- you either have to supply htmlContent or plainTextContent or both
- all empty arrays can be omitted
- the from address can be omitted if you configured a default from address
- attachments can be omitted
- attachments need a
mimeTypeanameandbase64Content replyTocan be omitted
When supplying an inline attachment "contentDisposition": "INLINE"
- you need a html part as well
- have a contentId
- reference it in the html part, but there is no validation for that!
Just build it with maven
mvn clean install
<dependency>
<groupId>de.kaffeekrone</groupId>
<artifactId>mail-drop</artifactId>
<version>XXX</version>
</dependency>be aware that docker commands are always environment dependent, especially networking, so take this as a rough example
# setup rabbitmq & mailcatcher as the receiving end
docker run -d -p 5672:5672 -p 15672:15672 --name rabbitmq docker.io/rabbitmq:3.8.9-management
docker run -d --name mailcatcher -p 1080:1080 -p 1025:1025 docker.io/schickling/mailcatcher
RABBITMQ_IP=$(docker inspect -f '{{range.NetworkSettings.Networks}}{{.IPAddress}}{{end}}' rabbitmq)
SMTP_HOST=$(docker inspect -f '{{range.NetworkSettings.Networks}}{{.IPAddress}}{{end}}' mailcatcher)
# start mail-drop
docker run --rm -e SPRING_MAIL_HOST=$SMTP_HOST -e SPRING_RABBITMQ_HOST=$RABBITMQ_IP ghcr.io/kaffeekrone/mail-drop:main
# send test mail
docker exec rabbitmq rabbitmqadmin publish exchange='mail-drop' routing_key='mail-drop' payload='{"mail":{"subject":"huhu","plainTextContent":"content🙉"},"recipients":["fun@bla.de"],"from":"defaultfromaddress@fancydomain.de"}'