<p>I’ve built a service that lives in a Docker container. As part of it’s required behavior, when receiving a gRPC request, it needs to send an email as a side effect. So imagine something like</p>

<pre><code>service MyExample {
  rpc ProcessAndSendEmail(MyData) returns (MyResponse) {}
}
</code></pre>

<p>where there’s an additional emission (adjacent to the request/response pattern) of an email message.</p>

<p>On a “typical” server deployment, I might have a postfix running ; if I were using a service, I’d just dial it’s SMTP endpoint. I don’t have either readily available in this case.</p>

<p>As I’m placing my service in a container and would like to deploy to kubernetes, I’m wondering what solutions work best? There may be a simple postfix-like Docker image I can deploy... I just don’t know.</p>

<p>There's several docker mailservers:</p>
<ul>
<li><a href="https://github.com/docker-mailserver/docker-mailserver" rel="nofollow noreferrer">https://github.com/docker-mailserver/docker-mailserver</a></li>
<li><a href="https://github.com/Mailu/Mailu" rel="nofollow noreferrer">https://github.com/Mailu/Mailu</a></li>
<li><a href="https://github.com/bokysan/docker-postfix" rel="nofollow noreferrer">https://github.com/bokysan/docker-postfix</a></li>
</ul>
<p>Helm charts:</p>
<ul>
<li><a href="https://github.com/docker-mailserver/docker-mailserver-helm" rel="nofollow noreferrer">https://github.com/docker-mailserver/docker-mailserver-helm</a></li>
<li><a href="https://github.com/Mailu/helm-charts" rel="nofollow noreferrer">https://github.com/Mailu/helm-charts</a></li>
<li><a href="https://github.com/bokysan/docker-postfix/tree/master/helm" rel="nofollow noreferrer">https://github.com/bokysan/docker-postfix/tree/master/helm</a></li>
</ul>
<p>Note that the top answer in <a href="https://www.reddit.com/r/kubernetes/comments/uf4r8v/easy_to_deploy_mail_server/" rel="nofollow noreferrer">this reddit thread</a> recommends signing up for a managed mail provider instead of trying to self-host your own.</p>
