Problems registering mailhosts

[ravenstar68]

Hi

I've previously registered my mail hosts with yourself, but I have changed my servers and wanted to register my current mail setup

The issue is the send from your servers in order to start the process is being rejected:

Connecting to mail.timothydutton.co.uk.:
smtpSend:smtpEnvelope (service@admin.spamcop.net, me@myaddress.co.uk): smtpTo rcpt to:me@myaddress.co.uk (450 4.7.1 : Helo command rejected: Host not found )

Sometimes, mailservers are temporarilly unavailable. If you believe you have entered your email address and other details correctly, you might just wait a few minutes (or 24 hours) and try again.

Checking the logs on my mail server I see this

Jul  7 18:11:22 mail postfix/smtpd[1489520]: warning: hostname vmx.spamcop.net does not resolve to address 184.94.240.100

Jul  7 18:11:22 mail postfix/smtpd[1489520]: NOQUEUE: reject: RCPT from unknown[184.94.240.100]: 450 4.7.1 <prod-sc-www03.spamcop.net>: Helo command rejected: Host not found; from=<service@admin.spamcop.net> to=<me@myaddress.co.uk> proto=SMTP helo=<prod-sc-www03.spamcop.net>

Doing a dig for vmx.spamcop.net I get this

vmx.spamcop.net. 300 IN A 184.94.240.112

So it looks to me as something has changed with your sending setup

Are you able to look into this?

Edited July 7, 2023 by ravenstar68
Removed email address

[ravenstar68]

I managed to solve the issue by whitelisting Spamcops HELO argument temporarily.

[gnarlymarley]

Was it a rule that sees "spam" in the hostname and blocks it? I have not see many spammers that actually use "spam" in their name.

[petzl]

23 hours ago, ravenstar68 said:

I managed to solve the issue by whitelisting Spamcops HELO argument temporarily.

here's a parse from my SpmCop email forward if it helps?
https://www.spamcop.net/sc?id=z6853349332z2acbb66cbd2eb939062d55e6fb57fc91z  
Received: from vmx.spamcop.net (HELO vmx5.spamcop.net) ([184.94.240.100])

[ninth]

3 hours ago, gnarlymarley said:

Was it a rule that sees "spam" in the hostname and blocks it? I have not see many spammers that actually use "spam" in their name.

I believe the word on its own is fine but in a shady claim such as this is not spam or junk or a scam it will get some points.

Edited July 9, 2023 by ninth
add

[ravenstar68]

The error message tells you what the issue is although the IP address of the server resolves back to vmx.spamcop.com - That's not the identity given in the HELO

The identity in the HELO is prod-sc-www03.spamcop.net

I added a rule in my postfix file /etc/postfix/helo_access.pcre to whitelist the hostname so it didn't go through the checks on the HELO identity - I removed it once I'd completed the Spamcap mail host configuration.

Here's a dig on the HELO identity.

 % dig prod-sc-www03.spamcop.net

; <<>> DiG 9.10.6 <<>> prod-sc-www03.spamcop.net
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 3536
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;prod-sc-www03.spamcop.net.	IN	A

;; AUTHORITY SECTION:
spamcop.net.		300	IN	SOA	ns1-93.akam.net. hostmaster.akamai.com. 2023052201 300 300 300 300

;; Query time: 43 msec
;; SERVER: fe80::c206:c3ff:fe3b:cc8d%12#53(fe80::c206:c3ff:fe3b:cc8d%12)
;; WHEN: Sun Jul 09 11:56:02 BST 2023
;; MSG SIZE  rcvd: 123

A sending server delivering to a mail exchanger should identify itself properly with its FQDN.  The  FQDN Should resolve back to the IP address, and the ideal configuration is for the reverse IP  to resolve back to the FQDN given in the HELO identity.

Really surprised to see this behaviour from Spamcaops setup.