Emails not received other end

[DavidJB]

We are finding that many emails sent by us from our domain are not reaching their destination, even though they are shown as delivered by Email Tracker, which at this stage we can only look back on for 1 week. It seems to have been an issue on and off for a few weeks. Seems to be emails with an attachment. How can I get tech support for this?

It seems that we are being filtered out as spam at the receiver's end, but they don't appear in their spam and junk folders. We had this issue repeatedly a few years ago with our previous provider, but this is a first since moving here.

Desperate, invoices are not being received by clients!

Regards, David

 

[zEitEr]

Hello David,

If 3rd-party mail servers mark emails originated from your server as SPAM, you might first of all make sure domains in behalf of which you email have SPF, rDNS, DKIM, DMARC configured correctly. If the all parts are completed fine and pass tests, then you will make sure the IP you are sending emails from is not backlisted in public RBLs. If even this step is fine, then you will need to contact the 3rd party server's support team for more details.

 

[sysdev]

Use internet.nl to check your email settings. Get a 100% score. It's pretty easy and shows if you have setup ipv6, dns, dmarc, dkim, caa, tlsa, whatever correctly. If you already use dmarc, make sure it's set to 'quarantine' so IF your mail does not pass everything, it's dropped in the users spambox and not blocked.

 

[Richard G]

Use internet.nl to check your email settings. Get a 100% score.

They are a bit too harsh. You don't need 100%. Because they are checking things like DANE can only be achieved by customisation in DA if I'm correct. That's not pretty easy. And internet.nl substracts points for that.
78% is a nice score and this is because I don't have DANE and no RPKI. And for RPKI you can do nothing either. Datacenter needs to fix that. I've already asked Hetzner and they refuse to do that, because their own RPKI is in good order according to them.
And this is with DNSSEC enabled, which is also not really required for correct mail delivery. So without DNSSEC the score will even be lower.

So that's already reasons you will not pretty easy be able to achieve a 100% score. A 70+ score is well enough if the most important things are ok.

@DavidJB I would first check the Exim logfiles as also attachments can be wiped by the system due to the /etc/system_filter.exim file. I've customized that one.
Check with mail-tester.com because there you should have a 10/10 score without attachments anyway. If you don't have a 10/10, then something is already not in perfect order, things which -can- easily be made in perfect order.
Presuming you're using your own mailserver and not a 3rd party.

Another way is to send a fake invoice to my address, which is also set quite strict, if I don't receive it either then maybe I can see in the logs what is happening. But tray mail-tester.com first anyway.

 

[sysdev]

Well, 100% might not be needed for e-mail only, might not even be possible if you have the wrong dc, but I find it worth the few minutes it takes to setup and it prevents a whole lot of finger pointing.

 

[zEitEr]

Check with mail-tester.com because there you should have a 10/10 score without attachments anyway. If you don't have a 10/10, then something is already not in perfect order, things which -can- easily be made in perfect order.

The bad thing about mail-tester is that they still do not support IPv6 (kindly correct me if I'm wrong). So the tests might show 10/10 for IPv4, and you might fail with IPv6.

 

[Richard G]

So the tests might show 10/10 for IPv4, and you might fail with IPv6.

That is correct in case of a system working with ipv6 only.
We work with ipv4 and 6. Ipv6 goes first if the receiving system also uses ipv6 and falls back to ipv4 if not.
But indeed mailtester does not support ipv6 as far as I know.
Are there already ipv6 only systems out there then?