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IDProjectCategoryView StatusLast Update
0005680Kali LinuxKali Websites & Docspublic2024-05-14 16:26
Reporterconstcast Assigned Toelwood  
Status closedResolutionreopened 
Summary0005680: No DNS entry for

Host does not have a DNS entry and might be blocked from sending mails for domains that implement SPAM prevention measures to only allow mail sending hosts with proper DNS entries:

NOQUEUE: reject: RCPT from unknown[]: 450 4.7.1 <>: Helo command rejected: Host not found;

Steps To Reproduce


; <<>> DiG 9.14.4 <<>>
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 13152
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

; EDNS: version: 0, flags:; udp: 4096
; IN A

;; AUTHORITY SECTION: 1178 IN SOA 1565718565 10800 3600 604800 10800

;; Query time: 19 msec
;; WHEN: Sat Sep 07 08:36:14 CEST 2019
;; MSG SIZE rcvd: 102




2019-09-07 17:39

administrator   ~0011063

Thanks, but we don't use that hostname for sending e-mail so the fact it does not exist has no relevance. If this is something that is interesting to you, you should really look up what MX records are and how they are used.



2019-09-08 06:37

reporter   ~0011064

Hi elwood,

you actually use the host name while sending mail. When sends out external mail, the following IP sends the email: The IP does EHLO with

Several mail servers (including mine) are configured to drop mails that are being send out with an non-existing DNS entry for the hostname in the EHLO message for spam blocking reasons. This results in the mails being dropped. You might want to consider adding a DNS name for this IP (and which is also being allowed to send mails for according to your SPF record), or configure the mail server to identify as another existing hostname while sending emails to avoid your mails being dropped at some systems.



2019-09-08 13:55

administrator   ~0011071

Thanks for the report @constcast.
Will be looking into it =)



2024-05-14 16:26

administrator   ~0019270

This shouldn't be an issue any more since we are no longer self-hosting email

Issue History

Date Modified Username Field Change
2019-09-07 06:39 constcast New Issue
2019-09-07 17:39 elwood Note Added: 0011063
2019-09-07 17:39 elwood Assigned To => elwood
2019-09-07 17:39 elwood Status new => closed
2019-09-07 17:39 elwood Resolution open => fixed
2019-09-08 06:37 constcast Status closed => feedback
2019-09-08 06:37 constcast Resolution fixed => reopened
2019-09-08 06:37 constcast Note Added: 0011064
2019-09-08 13:55 g0tmi1k Note Added: 0011071
2024-05-14 16:26 g0tmi1k Note Added: 0019270
2024-05-14 16:26 g0tmi1k Status feedback => closed