On 17/02/2023 17:39, steve-ALUG@hst.me.uk wrote:

Hi all

I have just seen a message saying that Gmail is going to reject all emails without an SPF set up, so I thought I'd try for my mail server.

Of course I have immediately run into trouble.

My email gets sent via a virgin media server, currently smtp.ntlworld.com but I may update to smtp.virginmedia.com in future

I used an SPF Wizard https://www.spfwizard.net

It generated

v=spf1 mx a a:smtp.ntlworld.com a:smtp.virginmedia.com ~all

which if I read it right, accepts my domain, or smtp.ntlworld.com or smtp.virginmedia.com as valid email handlers for my email, with a "soft fail". [I used a soft fail for debugging - I want to swap to hard fail, but can't until I get this right]

I've sent a couple of emails to test, and here's the snag.  By the time they get to google, they're coming from 212.54.57.96 212.54.57.97

If I do a whois on that, I get back ziggo.nl (VODAFONEZIGGO)

I expect email to smtp.ntlworld.com gets redirected to another server, or group of servers,  inside virgin media, no doubt with a name like MAILSERVER.virginmedia.com (for some value of MAILSERVER), and that's handled by a range of IP addresses.

How can I craft a valid SPF record, if I don't know which IP addresses or name to put in the spf?

Why is virgin media mail ending up on a server in NL, or is that just an out-of-date or wrong whois lookup?

Any ideas?????

I'm struggling!

Fixed!

Eventually I found

https://community.virginmedia.com/t5/Email/Sending-email-using-your-own-doma...

and included

include:_smtprelay.virginmedia.com

in my SPF record.  That file points to virgin media's list of email addresses used for mail sending.

FWIW I also have created a (do almost nothing) DMARC Record along the lines of what's on that website.  There was a slight error/omission in what was listed.  It should be of the format:

v=DMARC1; p=none; rua=mailto:reportaddress@domain

Steve