Email notifications not sending

[bimg21]

I have tried multiple ways of engineering the email notification setup, but none are working. Those I've tried include:

mailtos://mail.ecloud.global?to=*@seznam.cz&pass=*&user=*@murena.io
mailtos://mail.ecloud.global?user=*@murena.io:*?to=*@seznam.cz
mailtos://*@mail.ecloud.global?user=*@murena.io?to=*@seznam.cz
mailtos://&pass=*@mail.ecloud.global?user=*@murena.io?to=*@seznam.cz

The emails just don't send.

Version
v0.43.1

Expected behavior
Receiving emails with site changes.

Desktop (please complete the following information):

• OS: Ubuntu 22.04
• Browser: Firefox
• Version: 113.0.2 (64-bit)

** Notification debug logs context**
2023/06/30 16:09:21,000 - SENDING - null
2023-06-30 16:09:22,739 - WARNING - Sending email to "@seznam.cz" failed. Reason: {'@seznam.cz': (553, b'5.7.1 *@mail.ecloud.global: Sender address rejected: not owned by user @murena.io')}
2023-06-30 16:09:22,307 - DEBUG - Applying user credentials...
2023-06-30 16:09:22,119 - DEBUG - Securing connection with STARTTLS...
2023-06-30 16:09:21,747 - DEBUG - Connecting to remote SMTP server...
2023-06-30 16:09:21,741 - DEBUG - Delivery: mail.ecloud.global:587
2023-06-30 16:09:21,741 - DEBUG - Login ID: @murena.io
2023-06-30 16:09:21,741 - DEBUG - Email To: @seznam.cz
2023-06-30 16:09:21,741 - DEBUG - Email From: "changedetection.io" *@mail.ecloud.global
2023-06-30 16:09:21,737 - INFO - Notifying 1 service(s) asynchronously.
2023-06-30 16:09:21,736 - DEBUG - Loaded E-Mail URL: mailtos://:@mail.ecloud.global/%40seznam.cz?format=html&overflow=upstream&rto=4.0&cto=15&verify=yes&mode=starttls&from=%40mail.ecloud.global
2023-06-30 16:09:21,735 - INFO - Applying Custom Defaults
2023/06/30 16:08:38,000 - SENDING - null
2023-06-30 16:08:39,633 - WARNING - Sending email to "@seznam.cz" failed. Reason: {'@seznam.cz': (553, b'5.7.1 *@mail.ecloud.global: Sender address rejected: not owned by user @murena.io')}
2023-06-30 16:08:39,006 - DEBUG - Applying user credentials...
2023-06-30 16:08:38,805 - DEBUG - Securing connection with STARTTLS...
2023-06-30 16:08:38,042 - DEBUG - Connecting to remote SMTP server...
2023-06-30 16:08:38,039 - DEBUG - Delivery: mail.ecloud.global:587
2023-06-30 16:08:38,039 - DEBUG - Login ID: @murena.io
2023-06-30 16:08:38,038 - DEBUG - Email To: @seznam.cz
2023-06-30 16:08:38,038 - DEBUG - Email From: "changedetection.io" *@mail.ecloud.global
2023-06-30 16:08:38,036 - INFO - Notifying 1 service(s) asynchronously.
2023-06-30 16:08:38,035 - DEBUG - Loaded E-Mail URL: mailtos://:@mail.ecloud.global/%40seznam.cz?format=html&overflow=upstream&rto=4.0&cto=15&verify=yes&mode=starttls&from=%40mail.ecloud.global
2023-06-30 16:08:38,035 - INFO - Applying Custom Defaults
2023/06/30 16:08:16,000 - SENDING - null
2023-06-30 16:08:18,805 - WARNING - Sending email to "@seznam.cz" failed. Reason: {'@seznam.cz': (553, b'5.7.1 *@mail.ecloud.global: Sender address rejected: not owned by user @murena.io')}
2023-06-30 16:08:17,582 - DEBUG - Applying user credentials...
2023-06-30 16:08:16,963 - DEBUG - Securing connection with STARTTLS...
2023-06-30 16:08:16,036 - DEBUG - Connecting to remote SMTP server...
2023-06-30 16:08:16,027 - DEBUG - Delivery: mail.ecloud.global:587
2023-06-30 16:08:16,027 - DEBUG - Login ID: @murena.io
2023-06-30 16:08:16,027 - DEBUG - Email To: @seznam.cz
2023-06-30 16:08:16,026 - DEBUG - Email From: "changedetection.io" *@mail.ecloud.global
2023-06-30 16:08:16,022 - INFO - Notifying 1 service(s) asynchronously.
2023-06-30 16:08:16,021 - DEBUG - Loaded E-Mail URL: mailtos://:@mail.ecloud.global/%40seznam.cz?format=html&overflow=upstream&rto=4.0&cto=15&verify=yes&mode=starttls&from=%40mail.ecloud.global
2023-06-30 16:08:16,020 - INFO - Applying Custom Defaults

[dgtlmoon]

moved to discussions as per what is written in the ticket template

2023-06-30 16:09:22,739 - WARNING - Sending email to "@seznam.cz" failed. Reason: {'@seznam.cz': (553, b'5.7.1 [*@mail.ecloud.global](mailto:*@mail.ecloud.global): Sender address rejected: not owned by user @murena.io')}

looks like a problem with your provider? murena.io is not setup right?