Graylog 4.3.2 failed to send Email Notification

1. Describe your incident:
Working configuration in 4.2.10 for event email notification does not work in 4.3.2 version. When execute Test Notification gives me a error without any exception or hint in log.

2. Describe your environment:
OS - Rocky Linux release 8.6

Graylog- 4.3.2

MongoDB- 4.2.21

Elastic - 7.10.2

  • Service logs, configurations, and environment variables:
    My smtp server relay works on port 25 without authentication.


Email transport

transport_email_enabled = true

transport_email_hostname =

transport_email_port = 25

#transport_email_use_auth = true

#transport_email_auth_username = you

#transport_email_auth_password = secret

#transport_email_subject_prefix = [graylog]

3. What steps have you already taken to try and solve the problem?

I’ve installed new Graylog server 4.2 with same server.conf configuration and test mail working fine.
After upgrade to 4.3 error occurs again.
I’ve tried different combination in Notification Edit tab without success (i.e. to change remove/change sender address, Subject etc. ).

4. How can the community help?
Any help/hint will be appreciated.


Hello && Welcome

This is odd, I just update mine without issues. Couple question

  • Is you mail server on Graylog node? If so what Email type are sending these messages (i.e. sendmail, postfix,etc…)
  • Selinux/Apparmor enabled?
  • Did you check the email server log files? If so what does it show?
  • insure port 25 is open, sometime a reboot or upgrade, if not saved could close those ports to be blocked.
  • Insure the email server can send a test notification without the use of Graylog, this would narrow down where the issue is.

EDIT: Here is an example of mine

transport_email_enabled = true
transport_email_hostname = localhost
tansport_email_port = 25
transport_email_subject_prefix = [graylog]
transport_email_from_email =
transport_email_web_interface_url =

Using Sendmail on this server.

Hello, it looks like

transport_email_from_email =

in server.config fix the issue, which is strange because I’ve already have Sender in Graylog UI

Another thing is that transport_email_from_email = [] does not play any role since when I open test email source information properties From is that from Sender filed in UI, not transport_email_from_email.

Anyway, Thank you very much for hint!

In the end working config in Server.conf

transport_email_enabled = true

transport_email_hostname = gateway.myerver

transport_email_port = 25

transport_email_from_email =

1 Like


yep. had the same problem, adding the useless GRAYLOG_TRANSPORT_EMAIL_FROM_EMAIL fixes it.

I checked the upgrade notes and it’s not documented that GRAYLOG_TRANSPORT_EMAIL_FROM_EMAIL is suddenly required. And the error message could be a lot more helpful.

This fixed the problem for me as well.

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