I agree that that standard text for these emails is too "Nabble".
Most of our users only know that they want to subscribe to the "xyz forum/topic/list". They know nothing of Nabble.
I don't mind there being a standard text too much, but a change of wording/subject line to emphasise the name of the forum/topic/list with just an explanation of why the mail comes from nabble.com would be a good first step.
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.