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[8.001] SMTP Proxy blocks legitimate mail, cause "RDNS missing"

Copyright
Hi

our SMTP proxy (ASG 8.001) is blocking legitimate mail (for example from astaro.com) because of "RDNS missing":

---

H=(mx.astaro.com) [213.144.15.13]:51016 F= rejected RCPT : No RDNS entry for 213.144.15.13

---

>nslookup 213.144.15.13
Name:    mx.astaro.com
Address:  213.144.15.13

---

H=(ns3.ticketcorner.com) [195.47.231.137]:60788 F= rejected RCPT : No RDNS entry for 195.47.231.137

---

C:\Dokumente und Einstellungen\dtschan>nslookup 195.47.231.137
Name:    ns3.ticketcorner.com
Address:  195.47.231.137
---

I had to deactivate RDNS check completely to get these mails again. Our second SMTP proxy (ASG 7.506) doesn't show this false positives.

Anyone else seen this issue ?


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Parents
  • 0
    It looks like the Astaro is going straight to the root nameservers, and the response likely isn't fast enough for the SMTP Proxy.
    I use the DNS proxy on the Astaro, which forwards all DNS requests to OpenDNS.

    I wonder if the UP2Date didn't get the DNS configuration jumbled.  Have you tried to delete all of the forwarders in DNS, [Apply], re-enter the forwarders, [Apply]?

    Cheers - Bob
     
    Sophos UTM Community Moderator
    Sophos Certified Architect - UTM
    Sophos Certified Engineer - XG
    Gold Solution Partner since 2005
    MediaSoft, Inc. USA
Reply
  • 0
    It looks like the Astaro is going straight to the root nameservers, and the response likely isn't fast enough for the SMTP Proxy.
    I use the DNS proxy on the Astaro, which forwards all DNS requests to OpenDNS.

    I wonder if the UP2Date didn't get the DNS configuration jumbled.  Have you tried to delete all of the forwarders in DNS, [Apply], re-enter the forwarders, [Apply]?

    Cheers - Bob
     
    Sophos UTM Community Moderator
    Sophos Certified Architect - UTM
    Sophos Certified Engineer - XG
    Gold Solution Partner since 2005
    MediaSoft, Inc. USA
Children
  • 0 in reply to BAlfson
    Have you tried to delete all of the forwarders in DNS, [Apply], re-enter the forwarders, [Apply]?


    Right now, I deleted both OpenDNS forwarders, re-entered them, then I flushed the DNS cache. Afterwards I resolved the ip again and it seems like the same lookup answer:

    ---
    Trying "13.15.144.213.in-addr.arpa"

    ;; ->>HEADER
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