Stupid SMTP spam

Dear SMTP admins,

if you receive an email for which the SPF entry does not match, which suggests a hard fail and the DKIM entry either cannot be found or also does not match and you - quite correctly - conclude that this must be spam, then there is absolutely no need to inform the supposed author of the email about this.

If you want to inform them there is a correct way to do so. Just have a look at the DMARC RUA entry.

If you bounce these mails you are spamming the mail to someone who very likely has fuck all to do with it.

What you do with the mails locally is up to you. But if you are clearly instructed to throw away mails that don't match then you should probably just throw them away.