SMTP completely broke with the update to core-2026.3.4

[ghuh]

The problem

I update from from 2026.2 to 2026.3.4 and I got a repair saying that an automation was using an unknown action which is the notify email action.

What version of Home Assistant Core has the issue?

core-2026.3.4

What was the last working version of Home Assistant Core?

core-2026.2.x

What type of installation are you running?

Home Assistant OS

Integration causing the issue

SMTP

Link to integration documentation on our website

https://www.home-assistant.io/integrations/smtp/

Diagnostics information

No response

Example YAML snippet

Anything in the logs that might be useful for us?

Logger: homeassistant.components.notify
Source: components/notify/legacy.py:108
integration: Notifications (documentation, issues)
First occurred: 11:30:49 AM (1 occurrence)
Last logged: 11:30:49 AM

Error setting up platform smtp
Traceback (most recent call last):
  File "/usr/local/lib/python3.14/smtplib.py", line 405, in getreply
    line = self.file.readline(_MAXLINE + 1)
  File "/usr/local/lib/python3.14/socket.py", line 725, in readinto
    return self._sock.recv_into(b)
           ~~~~~~~~~~~~~~~~~~~~^^^
TimeoutError: timed out

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/notify/legacy.py", line 108, in async_setup_platform
    notify_service = await hass.async_add_executor_job(
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        platform.get_service, hass, p_config, discovery_info
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/usr/local/lib/python3.14/concurrent/futures/thread.py", line 86, in run
    result = ctx.run(self.task)
  File "/usr/local/lib/python3.14/concurrent/futures/thread.py", line 73, in run
    return fn(*args, **kwargs)
  File "/usr/src/homeassistant/homeassistant/components/smtp/notify.py", line 108, in get_service
    if mail_service.connection_is_valid():
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/usr/src/homeassistant/homeassistant/components/smtp/notify.py", line 172, in connection_is_valid
    server = self.connect()
  File "/usr/src/homeassistant/homeassistant/components/smtp/notify.py", line 158, in connect
    mail = smtplib.SMTP(self._server, self._port, timeout=self._timeout)
  File "/usr/local/lib/python3.14/smtplib.py", line 262, in __init__
    (code, msg) = self.connect(host, port)
                  ~~~~~~~~~~~~^^^^^^^^^^^^
  File "/usr/local/lib/python3.14/smtplib.py", line 350, in connect
    (code, msg) = self.getreply()
                  ~~~~~~~~~~~~~^^
  File "/usr/local/lib/python3.14/smtplib.py", line 408, in getreply
    raise SMTPServerDisconnected("Connection unexpectedly closed: "
                                 + str(e))
smtplib.SMTPServerDisconnected: Connection unexpectedly closed: timed out

Additional information

No response

[home-assistant]

@ghuh Thanks for reporting this issue!

Before we dive in, please make sure this isn't a duplicate by searching through existing issues. Also check recently closed issues, as your problem might already be fixed but not yet released.

https://github.com/home-assistant/core/issues?q=%20label%3A%22integration%3A%20smtp%22%20
_{^{(message by IssueContext)}}

---

smtp documentation
smtp source
_{^{(message by IssueLinks)}}

[ghuh]

As of core-2026.4.2 this is still broken.

I can run the "YAML configuration reloading" for "SMTP notify services" and that triggers the same log message as above, but nothing else happens.

All automations using smtp notifications are reporting "uses an unknown action".

[bbbburns]

I had this error and resolved it by changing the definition of my notification name in configuration.yaml from using dashes to using underscores, despite it having worked for at least a year with dashes. There are other issues in the past closed with no resolution that might have had similar causes:

https://bbbburns.com/home-assistant-smtp-notify-error/

#145015

The trace for my automation - that told me the automation was looking for something that didn't exist.

Error: Action notify.brian_smtp_jason_burns_team not found

Result:

params:
  domain: notify
  service: brian_smtp_jason_burns_team

But I had defined my configuration.yaml as dashes - so obviously what it was looking for did NOT exist.

notify:
  - name: "brian-smtp-jason-burns-team"

I changed my notification from dashes to underscores in configuration.yaml, restarted Home Assistant, and this automation error went away. The automations now find and use the notification successfully.

Edit: Although - now that I think about it - maybe the slugification wasn't the problem, and just restarting Home Assistant was all that was needed? The notify entity is only created on Home Assistant restart, so when I restarted Home Assistant and being able to reach the mail server at that time could have fixed this in my case.

[ghuh]

Both my configuration and the error message show underscores in the name. So I don't think that is the issue. I've tried reloading SMTP and restarting the whole server many times and that doesn't change anything.

[ghuh]

Well that's dumb. I changed my configuration from

  name: "email_it_alerts"

to

  name: email_it_alerts

reloaded the SMTP yaml and suddenly everything appears to be working again.

I'm pretty sure the quotes weren't the problem, but it seems like simply changing something causes it to start working again.

[issue-triage-workflows]

There hasn't been any activity on this issue recently. Due to the high number of incoming GitHub notifications, we have to clean some of the old issues, as many of them have already been resolved with the latest updates.
Please make sure to update to the latest Home Assistant version and check if that solves the issue. Let us know if that works for you by adding a comment 👍
This issue has now been marked as stale and will be closed if no further activity occurs. Thank you for your contributions.