SMTP setup, Docker + fix ports

SymphonySMTP/Dockerfile

@@ -0,0 +1,24 @@
+FROM ubuntu:latest
+LABEL authors="lumijiez"
+
+FROM maven:3.9.9-eclipse-temurin-21 AS build
+
+WORKDIR /app
+
+COPY pom.xml .
+
+RUN mvn dependency:go-offline
+
+COPY src /app/src
+
+RUN mvn clean package -DskipTests
+
+FROM openjdk:21
+
+WORKDIR /app
+
+COPY --from=build /app/target/SymphonySMTP-1.0-SNAPSHOT.jar /app/SymphonySMTP.jar
+
+EXPOSE 8090
+
+ENTRYPOINT ["java", "-jar", "SymphonySMTP.jar"]