2 votes
Accepted

How to delist DNSBL?

This problem we were facing were related to Microsoft Office 365 announcements of disabling the support of TLS older than 1.2 and it has no relation to blacklist or spam. Fixing this issue is by ...
Tarek Salah's user avatar
2 votes
Accepted

Postfix - NDR messages immediately when sent to a bad domain

Start by rejecting completely invalid mail by adding reject_non_fqdn_recipient and reject_unknown_recipient_domain to appropriate restriction table. Postfix can additionally REJECT messages via ...
anx's user avatar
  • 9,728
2 votes

Configure server to ignore NDRs to forged addresses/domains

In short, to prevent backscatter you configure your mailserver to reject an undesired e-mail message during the SMTP transaction, rather than accepting the message first and then rejecting it at a ...
HBruijn's user avatar
  • 80.3k

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