Replies to Gmail accounts being rejected

[#1]

I've just noticed that when I reply to an email from a Gmail account, my reply is rejected with the following message:

Reporting-MTA: dns; avasout-peh-002 [212.159.14.18]
Received-From-MTA: dns; [192.168.1.156] [90.255.142.189]
Arrival-Date: Fri, 24 Mar 2023 14:24:57 +0000


Final-recipient: rfc822; name@gmail.com
Diagnostic-Code: smtp; 550-5.7.26 This mail is unauthenticated, which poses a security risk to the

The problem only occurs when sending to a Gmail account and seems to be an authentication failure from my mail server. Something to do with a missing DKIM or SPF record. Is this something Plusnet would set up on their mail server?

Any help would be appreciated.

Thanks

OldCoggers 

[#2]

Two questions...

1. Are you sending from @account.plus.com or @your-domain.tld
2. Is your SMTP configuration using authentication

[#3]

Hi Townman, thanks for the quick response. In answer to your question:

1. I'm using my own domain, i.e. myname.net

2. The SMTP security settings are: Connection Security - None; Authentication Method - Password, transmitted insecurely

I've used these setting for about twenty years!

Cheers

OldCoggers

[#4]

@OldCoggers 

I've used these setting for about twenty years!

and 20 yrs ago they were fine, but I'm afraid with the increase in levels of spam detection (particularly by google)  , they are now not sufficient

You need to add an SPF record for your domain. Assuming you are sending via the Plusnet smtp relays then it should be

v=spf1 a mx include:_spf-internal.plus.net include:_spf-internal2.plus.net ~all

Also you should change your SMTP connection security to STARTTLS and use port 587

[#5]

Hi MisterW,

I've changed the Connection security to STARTTLS and am already using port 587.

However, I'm unclear where to add the SPF record. Plusnet host my domain, although I see by Googling that this is only because I've been with them for donkey's years and that they don't do it now. I use Thunderbird as my mail client, but can't see any reference to SPF in the settings 

Cheers

OldCoggers

[#6]

Interestingly, I've just tested sending an email from my gmail acct to my domain.net acct and I was able to reply without it being bounced. This is with the recommended security settings, but no SPF record.

Thanks!

I would still be interested in setting up an SPF record

Cheers

OldCoggers

[#7 · Accepted solution]

Plusnet host my domain, 

@OldCoggers  Ah! , then whilst there is no formal way of creating a SPF TXT record , there is a 'work around'

Create an MX record using the values below on your domain as follows using the domain configure option in the member centre. Login to the member centre and go to https://www.plus.net/my.html?action=domainv2 , click the 'configure' button and then add an MX record in the Additional DNS records section by clicking the 'Configure DNS records' button

Type: MX
Priority: 999999
Right Field: please-add-spf-records

That should create an SPF record (  may take up to about 6 hrs ). You can check if its created using the mxtoolbox site https://mxtoolbox.com/ , entering your domain and selecting SPF from the dropdown

[#8]

Thanks MisterW! I've managed to do that so I'll check later to see whether it's been set up correctly.

Cheers

OldCoggers

[#9]

Hi MisterW,

I left the dns record to propagate overnight, but mxtoolbox.com doesn't have anything showing this morning. Still, never mind, changing the security settings seems to have fixed the problem with replies to emails bouncing so thanks for that.

Cheers

Phill

[#10]

There was an instance a little while ago where this didn't seem to work first time. Removing and reading the MX record worked. Does the mx record show in mxtollbox ?

[#11]

If the domain in question is the one you’ve signed up to the Community with, then happy to confirm that does now have a SPF Record, according to the MX Toolbox. 

[#12]

Hi Gandalf, thanks, but I am a little confused. If I run mxtoolbox.com on my domain *****n.net, the first page shows a green tick against the DNS Record Found, but when click on the green tick, it goes to a page saying DNS Record Not Found.

Unless, on the line below DNS Record Found, there is a line showing Reported by ns2.force9.net. Is this the DNS record? If I click Transcript, I see two entries, neither of which seem to mention anything about SPF.

As you can probably tell, my knowledge here is a little flaky!

Cheers

OldCoggers

[#13]

Having run the initial MX lookup on your domain using mxtoolbox, there should now be a drop down arrow next to the MX LOOKUP button. Use that to select spf lookup and then click

[#14]

Aah, got it, thanks. It seems I do have an SPF after all!

Cheers

OldCoggers

[#15]

Thanks for this thread, folks - covers my scenario exactly.

(I'm currently at the 6 hour wait step 😀)

I wonder, though:  Couldn't or should Plusnet just trigger the creation of this record automatically on all the domains they host (without an SPF record already or some other suitable criteria)?

Cheers,

Mike.