Byom mail anhang

I think you meant to ask "What is BYOM and what is anhang?"

BYOM stands for "Bring Your Own Mail" and is a term used in the context of email marketing and email automation. It refers to the practice of sending personalized and targeted emails to customers or prospects using their own email addresses, rather than using a generic email address or a mailing list.

Anhang, on the other hand, is a German word that means "attachment" or "appendix". In the context of email, anhang refers to a file or document that is attached to an email message.

So, if someone asks you to "BYOM anhang", they are asking you to bring your own attachment or file to be sent via email.