emailgtw probe "HELO" string
Article ID: 229420
Updated On:
Products
Issue/Introduction
We cannot use our Data Center' open relay email server because the emailgtw probe sends out the HELO message with its hostname.
We need to be able to set the HELO string manually to use the FQDN our server IP resolves back to.
Long story short, https://talosintelligence.com/ is reporting our Nimsoft server as BAD (poor reputation) because of this mismatch.
Is there a way to manipulate the HELO string sent out by the emailgtw probe to match the data in our SPF record?
Oct 25 12:37:39:294 emailgtw: test_smtp_login from 10.xx.xxx.xxx/59799
Oct 25 12:37:39:299 emailgtw: [Trying IP address [192.xx.xxx.xxx]]
Oct 25 12:37:39:668 emailgtw: 220 xxxxx.smtp.xxxxxxxx.com ESMTP Postfix
Oct 25 12:37:39:668 emailgtw: EHLO host1xxxxxx.abc.xxxxxxx.net
Oct 25 12:37:39:851 emailgtw: 250-xxxxx.xxxx.xxxxxxxx.com
Oct 25 12:37:39:851 emailgtw: 250-PIPELINING
Oct 25 12:37:39:851 emailgtw: 250-SIZE
Oct 25 12:37:39:851 emailgtw: 250-VRFY
Oct 25 12:37:39:851 emailgtw: 250-ETRN
Oct 25 12:37:39:851 emailgtw: 250-STARTTLS
Oct 25 12:37:39:851 emailgtw: 250-ENHANCEDSTATUSCODES
Oct 25 12:37:39:851 emailgtw: 250-8BITMIME
Oct 25 12:37:39:851 emailgtw: 250 DSN
Oct 25 12:37:39:851 emailgtw: (cmd_test_smtp_login) smtp_open succeeded
Oct 25 12:37:39:851 emailgtw: (cmd_test_smtp_login) no user specified, not testing authentication
Oct 25 12:37:39:851 emailgtw: QUIT
Oct 25 12:37:40:035 emailgtw: 221 2.0.0 Bye
Hope you can help, this is VERY important (to be able to rely on email functioning properly).
Environment
Component : UIM - EMAILGTW
Cause
Cisco has an emailserver on the market called Talos, which will require the EHLO message sent out to match the FQDN returned by the pointer of your public IP.
RFC5321 calls for it to be implemented like that.
Resolution
Current workaround:
Customer installed Postfix to mediate between the emailgtw probe and the SMTP server, so they can set the outgoing EHLO to use the FQDN they registered.
As per Development/Engineering, the emailgtw probe is currently 'working as designed.'
The ability to manually set the HELO string to use the FQDN your server IP resolves back to is not currently supported.
This is considered an enhancement.
Please feel free to enter an enhancement request (Idea) for this to be added to the emailgtw probe. Note that once you enter the enhancement/idea, others can upvote the Idea.
You can add an Idea (enhancement request) by referencing this KB Article->
Additional Information
Also, please feel free to contact your Account Rep regarding the business impact/urgency if you would like to try and get this prioritized on the UIM product roadmap.
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