Emails to GMail accounts being rejected

[#1]

I am getting what appear to be similar rejections to some that have been reported in other posts, when sending to gmail addresses.  The message suggests this is something to do with verification issues mentioned in other posts (e.g. https://community.plus.net/t5/Email/Blank-Error-Message/td-p/1859134  from Feb 2022), and I am wondering if my practice of using the "sent from" option in desktop Outlook is causing this issue.  The message I'm getting:  

Like some other users whose posts I've seen, I have been using my Force9 account for many years to send and receive emails for a domain I use, that doesn't have a .f9.co.uk name.  Emails to that domain are all forwarded to my Force9 address, and I send via relay.force9.net.  In my cases, the rejecting server appears to belong to Plusnet, I assume as part of the AV system, but the fact that this is only just happening suggests to me that something has changed.  The incompletely-formed error text is also a puzzle.  Can anyone help?

[#2]

@iainmackay, the rejecting server is the one you've blanked out.  The Plusnet server that is listed is the reporting server.  ie Plusnet server has created a connection to the one that is blanked out and sent it some info.  That other server has then rejected the message.  It is then for that other server (the Plusnet one listed in this case) to report that back to you.

The issue is that Google have made changes so that at least some of the messages have are rejected if there isn't SPF or DKIM records present.

One "solution", as detailed above, is to create an SPF record for your domain.

[#3]

@iainmackay 

This is the Google communication on this:  https://support.google.com/a/answer/174124?hl=en

The important sentence is: Google performs random checks on new sender messages to personal Gmail accounts to verify they’re authenticated. Messages without at least one of these authentication methods will be rejected or marked as spam.

This suggests to me a reason why some emails get through.

[#4]

@iainmackay, Sorry, I thought this was a different thread when I commented about the method for adding SPF records being above. If the domain is hosted by Plusnet then this is a good post of how to add SPF records for sending via Plusnets servers: https://community.plus.net/t5/Email/Replies-to-Gmail-accounts-being-rejected/m-p/1914861#M42628

[#5]

This error relates to outgoing server authentication (or lack off)

Here's the setting in Outlook:-

[#6]

Ah!  Sorry @pjmarsh , the blanked "server" is my desktop PC, which is why I blanked out its details.  This implies that it's my own instance of Outlook desktop that's refusing to send my email?  @Baldrick1 , that makes sense but for the fact that the message seemed to be coming from my own PC...  I have sent you a pm with more details in the hope you can advise me.

@Browni that is the way my Outlook account settings are, specifying relay.force9.net on port 587.

My domain is hosted by fasthosts, with all emails forwarded to my Force9 address.

This is beyond my cunning, so can anyone suggest what I need to do?

[#7]

Sorry, that is likely my mistake then.  I'd still suspect it is related to SPF records (or lack of) though.

[#8]

@iainmackay 

I don't really have time to come back in detail today so I'm sorry if this email is rushed and possibly garbled. Superuser @pjmarsh  is the expert here, but my comments.

I do not use use Fasthosts and currently don't understand how you have configured your system. Don't Fasthosts provide any email services?

I have two domains. I use Outlook 2019 (part of the Microsoft Office suite) as my Email client.

The first domain has full send and receive capability and that is simply set to send and receive using their facilities.

The second is closer to your set up. The domain host (Namesco) only provide an inbox unless I pay more, so my set up is:

My Outlook settings are that the sender is set in Outlook to be from the Namesco hosted domain, but I send through the Plusnet SMTP server, so these are the Plusnet send settings. As the emails are identified as coming from Namesco, replies are sent to this address. For receiving I download the emails direct from Namesco, so the Namesco receive settings are used in Outlook. To avoid issues with Google I have added the Plusnet spf record to my Namesco domain, so there is authentication that the email has come from a legitimate source.

No email forwarding is involved.

[#9]

I do not use use Fasthosts and currently don't understand how you have configured your system. Don't Fasthosts provide any email services?

I think they provide just a domain registration and basic email forwarding facility. 

[#10]

Thank you very much @Baldrick1 .  Your setup is very similar to mine, the only differences I can see being the Outlook version (I have Microsoft® Outlook® for Microsoft 365 MSO (Version 2304 Build 16.0.16327.20200) 64-bit) and that you collect inbound mail from your domain hosting ISP while I use the forwarding option.  This has been like this for so long that I can't recall why I opted for that, but probably because, like you, I'd need to pay more for an alternative solution.

I shall do some more self-education on SPF records to see if that will help.  Meanwhile, thanks for your assistance.

[#11]

So in summary, you are using Plusnet's SMTP servers to send email from a third party domain name to Gmail?

If that is the case, you will fall foul of various non-mandatory standards imposed by Gmail...

1. The connection to the SMTP server (relay.plus.net) MUST be authenticated - if your device is connecting over the Plusnet network, you can send emails without using a username and password, but some receivers will not accept emails sent in that manner - see the response from @Browni 
2. The sending DOMAIN must have a SPF record indicating which SMTP servers are valid for the domain name - this you should be able to set up with your domain name host service in their DNS configuration
3. The sending service should use DKIM - this is not something you can effect using a third party domain when using Plusnet's SMTP relay services - HOWEVER if the sending address is mailbox@account.plus.com DKIM signing will be applied

Frankly hosting a domain on a third party environment, forwarding inbound mail to another hosting provider and than expecting to email to Gmail with out issue is a somewhat forlorn expectation!  One should always use the SMTP service associated with the domain's MX server.

Moderators Note: Typo corrected

[#12]

Thank you @Townman for this very clear explanation!  I guess the world has overtaken what seemed, previously, to be an acceptable working solution.  I frankly can't remember all the reasons why I ended up in this situation - probably a combination of cost of hosting the domain on Plusnet and unwillingness to move my email service away (my Force9 email address should indicate how long I've been here).  It looks as if I ought to try using the Fasthosts SMTP service for sending, then.  Another option would be to abandon using my old third-party domain for email altogether;  I retained it partly for sentimental reasons (it was set up for the band I used to play in) and also because all my contacts have used it for a very long time, so the usual traumas would accompany having to move away from it.  Decision time...

[#13]

Hi Iain,

There are a multitude of options for you - personally I would not start by saying goodbye to your domain name, especially as (a) it is well known amongst your network and (b) it has sentimental value.  I would look at getting your domain fully hosted for email, rather than trying to bend forwarding services.  IMPORTANT where forwarding services are concerned, it is imperative that SRS in implemented, without which SPF can be impaired.  IIRC Fasthosts does not implement SRS ... but such would only impact inbound emails.

Which Fasthosts product do you use?  See Using Fasthosts SMTP servers

Fasthosts charge £2.20pcm (out of the introductory period) for 2x 2GB mailboxes.

There are other providers at similar prices with differing technical details, for example Hosting - Shell Accounts - UK-based - Mythic Beasts (mythic-beasts.com) offers email functionality very similar to Plusnet's starting at £2pcm.

[#14]

Once again thanks @Townman - I need to get to grips with this.  The only product I have with Fasthosts is my domain name - everything else I do with my Force9 account, including hosting the website of the domain (the URL is masked).  Perhaps this, too, will eventually generate issues!

I shall consider my options.    

[#15]

...and the latest bombshell:  I just rang Plusnet support desk to see if I could talk to someone specifically about getting the syntax right for adding an SPF record to my externally hosted domain's DNS, and was told: 

Plusnet is ceasing all support for email and will not be offering an email service in the future!

When I asked when they had intended to tell me this, I was told the emails to customers had not gone out yet but would be in "about a couple of months".  In future, Plusnet intends to offer just phone and broadband.

I suggested that dropping this on customers with such short notice wasn't going to make Plusnet look good, and he promised to feed this back!!!

So anyway, it looks as if my decision on whether to move my email service to another provider has been made for me.