https://prepaid-host.com/de/blog/reverse-dns-ptr-eintrag-eigene-ip-spam-e-mails Prepaid-Host Blog de 2026-09-14T10:47:16+02:00 Reverse DNS für die eigene IP: Warum ohne PTR-Eintrag E-Mails im Spam landen https://prepaid-host.com/en/blog/reverse-dns-ptr-record-email-spam Prepaid-Host Blog en 2026-09-14T10:47:16+02:00 Reverse DNS for Your Own IP: Why Emails Land in Spam Without a PTR Record https://prepaid-host.com/zh/blog/reverse-dns-ptr-record-email-spam Prepaid-Host Blog zh-cn 2026-09-14T10:47:16+02:00 为自己的IP设置反向DNS:为什么没有PTR记录邮件会被当作垃圾邮件