Experiencing an issue when attempting to send an email to any Gmail address

OS type and version Ubuntu Linux 20.04.6
Webmin version 2.013
Virtualmin version 7.5
Related packages SUGGESTED

I’m experiencing an issue when attempting to send an email to any Gmail address using Roundcube. I’m receiving an error message stating ‘Undelivered Mail Returned to Sender’.

Here is the complete details.
host gmail-smtp-in.l.google . com[] said:
Our system has detected that this
message is 550-5.7.1 likely unsolicited mail.

Please help me to fix this issue.

Thank you!

https://mxtoolbox.com/ is your friend. Use the email health tool

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There are a lot of issues that might cause this. Is there a link in the headers to visit and investigate.?


found this issue.

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Good deal, that will do it!
Bookmark that site that Stephan provided. It is a great tool.


How to add SPF, DKIM and DMARC?

Thank you!

You probably doing the dns externally, then check the suggested DNS records in Server Configuration.
If you see no DKIM secords you need to turn it on at Email Setting–>DomainKeys Identified Mail
SPF and DMARC are just DNS records. DKIM is a key added to the sent emails from your system and verified by the DNS key in the TXT record.

Google it and check the forums for more detail info
Dmarc record is not in the suggested, but its the simplest record.
check cloudfare docs

Thank you very much, Stefan, for the update. I have attached a screenshot of the DNS records in the server configuration. However, I couldn’t find any option for DKIM in the server configuration.


Could you please guide me to the location of Email settings in Virtualmin?


The bottom set of menu items, below the ones you show above.

Email Settings, DomainKeys Identified Mail.

Sorry, I don’t have time for a screen capture right now.

please check the screenshot image of my server “Features and Plugins”.

I think i have to installed the DKIM module. am i right?

Thank you!

If you are not hosting DNS on the Virtualmin server, you should not have the DNS feature enabled. When you turn it off, Virtualmin will provide a page of suggested DNS records, which will include SPF and the DKIM record.

DKIM is not a module you have to install (and the dependencies are probably already installed, if you used our install script). It’s just an option you turn on, and it is documented: DomainKeys Identified Mail – Virtualmin

As an addendum, I’ve found it better to wait 24 hours or more after setting up SPF and DKIM before setting up DMARC. Perfectly-good DMARC will fail to validate until the DNS changes for SPF and DKIM propagate.

It may be less true nowadays than it was when I was young, back when ISDN was considered fast and horses and buggies roamed the streets of Olde Brooklyn. But old habits die hard.


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