[rails]

Do you know of any articles or information in general, how these hard things (ip control, bounce, ...) are done?

[gerardnico]

Bounce is an email send by the server when it can deliver an email. You just need to parse it.

Ip control is generally done via the dmarc report that you also get as email from email provider. https://datacadamia.com/marketing/email/dmarc