[GH-ISSUE #480] Intermittent deliverability #313

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opened 2026-03-15 13:50:25 +03:00 by kerem · 3 comments
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Originally created by @looksystems on GitHub (Apr 8, 2025).
Original GitHub issue: https://github.com/axllent/mailpit/issues/480

I've used mailpit on my local machine and it's invaluable, thank you.

Recently, I deployed it to a kubernetes cluster but am having problems with "intermittent" deliverability.

From the same application, there are times when emails come straight through to mailpit and other times they just appear to get "lost" ie. logging in the application just before sending is successful and no exceptions are recorded.

Using latest release, as of today.

Kubernetes config:


apiVersion: v1
kind: ConfigMap
metadata:
namespace: services-ns
name: mailpit-service-config
data:
MP_VERBOSE: "true"
MP_UI_AUTH: "admin:***"


apiVersion: apps/v1
kind: Deployment
metadata:
namespace: services-ns
name: mailpit-service-deployment
spec:
selector:
matchLabels:
app.kubernetes.io/name: mailpit-service-app
replicas: 1
template:
metadata:
labels:
app.kubernetes.io/name: mailpit-service-app
spec:
containers:
- image: axllent/mailpit:latest
imagePullPolicy: Always
name: mailpit-service-app
ports:
- containerPort: 8025
protocol: TCP
name: http
- containerPort: 1025
protocol: TCP
name: smtp-tcp
envFrom:
- configMapRef:
name: mailpit-service-config


apiVersion: v1
kind: Service
metadata:
namespace: services-ns
name: mailpit-service-service
spec:
ports:
- port: 8025
protocol: TCP
name: http-sv
targetPort: http
- port: 1025
protocol: TCP
name: smtp-sv-tcp
targetPort: smtp-tcp
type: NodePort
selector:
app.kubernetes.io/name: mailpit-service-app


apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
namespace: services-ns
name: mailpit-service-ingress
annotations:
alb.ingress.kubernetes.io/certificate-arn: arn:aws:acm:eu-west-1:redacted:certificate/redacted
alb.ingress.kubernetes.io/listen-ports: '[{"HTTPS": 443}]'
alb.ingress.kubernetes.io/scheme: internet-facing
alb.ingress.kubernetes.io/target-type: ip
spec:
ingressClassName: alb
rules:
- host: mailpit.reacted.domain
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: mailpit-service-service
port:
number: 8025
tls:
- hosts:
- mailpit.reacted.domain

Laravel application sending via SMTP to:

MAIL_FROM_NAME: "Test User"
MAIL_FROM_ADDRESS: "no-reply@redacted.domain"
MAIL_HOST: mailpit-service-service.services-ns.svc.cluster.local
MAIL_MAILER: "smtp"
MAIL_PORT: "1025"

Is this a known issue or have I configured something incorrectly?

Any help or assistance would be greatly appreciated. Thank you.

Originally created by @looksystems on GitHub (Apr 8, 2025). Original GitHub issue: https://github.com/axllent/mailpit/issues/480 I've used mailpit on my local machine and it's invaluable, thank you. Recently, I deployed it to a kubernetes cluster but am having problems with "intermittent" deliverability. From the same application, there are times when emails come straight through to mailpit and other times they just appear to get "lost" ie. logging in the application just before sending is successful and no exceptions are recorded. Using latest release, as of today. Kubernetes config: --- apiVersion: v1 kind: ConfigMap metadata: namespace: services-ns name: mailpit-service-config data: MP_VERBOSE: "true" MP_UI_AUTH: "admin:***" --- apiVersion: apps/v1 kind: Deployment metadata: namespace: services-ns name: mailpit-service-deployment spec: selector: matchLabels: app.kubernetes.io/name: mailpit-service-app replicas: 1 template: metadata: labels: app.kubernetes.io/name: mailpit-service-app spec: containers: - image: axllent/mailpit:latest imagePullPolicy: Always name: mailpit-service-app ports: - containerPort: 8025 protocol: TCP name: http - containerPort: 1025 protocol: TCP name: smtp-tcp envFrom: - configMapRef: name: mailpit-service-config --- apiVersion: v1 kind: Service metadata: namespace: services-ns name: mailpit-service-service spec: ports: - port: 8025 protocol: TCP name: http-sv targetPort: http - port: 1025 protocol: TCP name: smtp-sv-tcp targetPort: smtp-tcp type: NodePort selector: app.kubernetes.io/name: mailpit-service-app --- apiVersion: networking.k8s.io/v1 kind: Ingress metadata: namespace: services-ns name: mailpit-service-ingress annotations: alb.ingress.kubernetes.io/certificate-arn: arn:aws:acm:eu-west-1:redacted:certificate/redacted alb.ingress.kubernetes.io/listen-ports: '[{"HTTPS": 443}]' alb.ingress.kubernetes.io/scheme: internet-facing alb.ingress.kubernetes.io/target-type: ip spec: ingressClassName: alb rules: - host: mailpit.reacted.domain http: paths: - path: / pathType: Prefix backend: service: name: mailpit-service-service port: number: 8025 tls: - hosts: - mailpit.reacted.domain Laravel application sending via SMTP to: MAIL_FROM_NAME: "Test User" MAIL_FROM_ADDRESS: "no-reply@redacted.domain" MAIL_HOST: mailpit-service-service.services-ns.svc.cluster.local MAIL_MAILER: "smtp" MAIL_PORT: "1025" Is this a known issue or have I configured something incorrectly? Any help or assistance would be greatly appreciated. Thank you.
kerem 2026-03-15 13:50:25 +03:00
  • closed this issue
  • added the
    stale
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Author
Owner

@axllent commented on GitHub (Apr 8, 2025):

I'm afraid I can't be of any use with regards to Kubernetes (lack of experience), but I can maybe help you work out what's going on.

When you say intermittent issues, what actually happens when these messages get lost? Are they actually delivered via SMTP, or is that what sometimes works and sometimes doesn't? If they get delivered (according to the client), do they appear in the web UI when you manually refresh the browser?

Any Internal issues in Mailpit (eg: problem accessing or writing to the database etc) will be logged, so I'm assuming this should be easy to debug.

<!-- gh-comment-id:2787520979 --> @axllent commented on GitHub (Apr 8, 2025): I'm afraid I can't be of any use with regards to Kubernetes (lack of experience), but I can maybe help you work out what's going on. When you say intermittent issues, what actually happens when these messages get lost? Are they actually delivered via SMTP, or is that what sometimes works and sometimes doesn't? If they get delivered (according to the client), do they appear in the web UI when you **manually refresh** the browser? Any Internal issues in Mailpit (eg: problem accessing or writing to the database etc) will be logged, so I'm assuming this should be easy to debug.
Author
Owner

@github-actions[bot] commented on GitHub (Apr 16, 2025):

This issue has been marked as stale because it has been open for 7 days with no activity.

<!-- gh-comment-id:2808004482 --> @github-actions[bot] commented on GitHub (Apr 16, 2025): This issue has been marked as stale because it has been open for 7 days with no activity.
Author
Owner

@github-actions[bot] commented on GitHub (Apr 20, 2025):

This issue was closed because there has been no activity since being marked as stale.

<!-- gh-comment-id:2816947882 --> @github-actions[bot] commented on GitHub (Apr 20, 2025): This issue was closed because there has been no activity since being marked as stale.
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