Why are my e-mails sent via the GateManager "www.gatemanager.ch" no longer sent with the e-mail sender address I specified?

Devices which are locally connected to the SiteManager can use it as a simple SMTP server via port 25 to send e-mails. The SiteManager itself has no SMTP server functionality, but forwards this e-mail to the GateManager which sends it via an e-mail provider. In this case, e-mail clients on the devices could use any e-mail sender, which in turn could lead to misuse. Modern e-mail servers check incoming e-mails by means of various contents such as MX, DKIM, SPF records, so that the identity of the sender can be checked and whether he is authorized to send under this e-mail address. This had led to e-mails being rejected by servers time and again or various senders even ending up on black lists.
Therefore, from 01.02.2022 we will send all e-mails which are sent via the GateManager www.gatemanager.ch with the fixed e-mail sender address do-not-noreply@gatemanager.ch , so that they can be verified. The incoming sender address will be ignored.
Basic recommendation for e-mail dispatch:
Instead of sending e-mail via GateManager, use direct e-mail sending via SiteManager whenever possible. For this you only need one forwarding rule.
This offers several advantages, e.g. encrypted and authenticated e-mails can be sent via your provider, on the other hand it ensures that e-mails can be sent reliably if there is no connection to the GateManager.
Note for users who had sent e-mails for alerting purposes via the GateManager:
The e-mail sender address can no longer be used to identify the location of the alert. Use the content of the e-mail header or body to store this information instead.