I would like to set up notification emails from my computer and a NAS server for certain events. However I don't want to leave my email password on the systems. Are there solutions?
Ideally I would like something similar to SSH private key authentication, where I could generate "keys"/credentials for each system (or even just one for notifications in general will do), preferably with reduced privileges (such as only being used to send email and not log in to my email account).
I thought of email aliases, and Hotmail/Outlook is interesting due to the possibility of preventing aliases from being used for account login, but to my knowledge they cannot use a different password from the primary account. This is many-emails-one-password, while I'm looking more for one-email-many-credentials.
Gmail's SMTP relay service seems to do something similar to what I want but requires my credentials, and/or creates OAuth credentials for a project, which I'm not sure can be used by a system just expecting email, password, and SMTP server.
Of course the easy way would be to create a new email account just for notifications, but it's an extra account, and the credentials would still be common between the systems.
What are the options for this common use-case?