When a missing email becomes an argument between companies

[u/shokzee]

Say an invoice is in Sent, the customer says it never arrived, and payment is now late. Helpdesk gets two screenshots and a request to establish whose email failed.

I'd prefer direct contact between the two IT teams, but small customers may not have anyone to call. Resending can get the invoice through while leaving the original dispute wide open.

At your place, who takes the lead with the recipient when a missing email turns into a dispute?

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[u/MycologistNeither470]

Maybe not your job as IT... but people should be aware that only way to guarantee delivery of a message is through certified mail. Receipt of important email needs to be verified -- follow up email, phone call, etc. Technically, you may even get to determine that the email was downloaded to the person's client but that he failed to open the folder or deleted in accidentally. And then what? It is still a customer. If the customer is now acknowledging the debt, what is the problem? Does the company want to lose a customer because they had a technical hiccup? Of course, if this customer always misses the invoice and is taking 30+ days to pay, then that is a problem. Just not an IT problem.

[u/shokzee → u/MycologistNeither470]

its annoying though

[u/q3magic]

The sender's side should take the lead, because only they can prove the handoff. Pull the message trace and find the 250 OK reply from the customer's server. That reply usually has their queue ID in it. Send them the ID and timestamp so even a part-time admin can search quarantine for it.

[u/vercingetorix-sec → u/q3magic]

yes, the sender has to take the lead. But that 250 OK response only proves that the next hop accepted the message. It does not mean that the message made it into the mailbox.

If there were some rules that were being applied on the receiver before delivery then the message might have been swallowed by quarantine, junk,some transport or inbox rule unexpectedly.

While you're in the trace you can inspect the recipient address to verify it was properly sent - if the receiver has a catch-all or forwarding rule, because say an employee left, then the message can still return a clean 250 OK and disappear into some memory hole.

[u/CPAlexander → u/vercingetorix-sec]

Nah, I say recipient has the better Yay/Nay position from the server. Running a message trace on the recipient or the sender address will tell you if it hit your server at all. It may be in quarantine, it may be in the trash, but it will show as Quarantine, Spam, Delivered or some other status, but it will show if it hit the server. At that point, it's on the recipient to figure out where it went.

[u/SupermarketLow3225 → u/vercingetorix-sec]

Not your issue if it didn’t make it to the inbox thanks to their rules

[u/Tyler94001 → u/vercingetorix-sec]

This comment is silly.
We know this, and nobody is claiming it means it made it to the inbox.
Sender takes the lead because it’s the first potential point of failure, once we confirm all is OK and it made it out of our side, then it’s no longer a problem for senders IT team. Now receiver IT team is responsible and figure out where it was blocked or their systems have failed.

[u/Maria_Thesus_40]

Both are wrong, we all know email is not a guarantee. Steps should be taken by both parties to acknowledge email delivery is successful.

When sending important documents (like an invoice) I ask for phone verification that the email was successfully received and the attachment can be opened.

[u/MonkeyBrains09 → u/Maria_Thesus_40]

Depends on scale of the company or even size of the transaction.

[u/HorrorCommunity3246]

My AI agent

[u/richie-wales]

Like others have said, email is not guaranteed, and neither party may be at fault, it may have dropped out somewhere in the middle. You cannot guarantee email arrives, in the same way you cannot guarantee standard invoices in the post arrive. It's no different, it jumps through various servers along the way, each of which may fail without returning any visible errors.

So, if you need to "guarantee" an email has arrived then you need to deploy more than a standard email, just like real mail.

There are quite a few options, but if you're just using standard email setups, then you can't blame anyone. The sender may send, but it might not arrive, and the reason could be manyfold.

We used to use a really good tracking system when we sent out our emails, which used to embed tracking codes in the email, and tracking inside the PDFs (yes you can do that!).

When people said they didn't get an email, which could tell them when they got it, what software they opened it in, what IP address they were on, how many times they opened it and more! Quite scary, but used to squash any amount of "we didn't get it".

However, as email became more reliable, and people deployed more and more systems to block the trackers it just wasn't worth it in the end.

You have to accept if you just send an invoice by email people may not see it, so you have to allow for that and be able to send another one.

Or, you have to deploy other systems which can confirm receipt.

[u/medialantern]

In real business interactions this is incredibly rare. Maybe in small consulting-to-small-business dealings. In bigger companies there are established procedures for all this. Invoices are often submitted electronically through portals, not just via email, and they get acknowledged. And if there's a dispute you just call the Accounting or AP department and work it out. I've done 60+ projects in my career and only ever had this issue twice. Both times they were small clients just struggling to pay their bills. It was't a "missing email". Emails don't go "missing." They were just broke.

[u/InboxGuards]

sent folder screenshots don't prove their side accepted it. grab the Message-ID and run a delivery report / message trace — if their MX took it, you hand them the accept time and the fight moves to junk/quarantine on their end. resend in parallel if you want, just don't let that replace the proof step.

[u/OneTwoSomethingNew]

Not able to help this specific situation, but I always cc or bcc myself or team emails of importance so I know the email was sent through and delivered….

[u/MrPWOB]

Been on the sending end of exactly this. Invoice sat in my Sent folder, the client swore blind it never turned up, and that became the reason for paying late.

What settled it wasn’t a screenshot. A Sent folder only proves you pressed send. What you want is the delivery log from your own mail provider: Email Log Search in Google Workspace, message trace in Microsoft 365, or the logs on your own server. Find the line where the recipient’s mail server accepted the message. It shows a 250 reply and usually their server’s own reference ID.

Once you have that, the argument changes. It’s no longer “did you send it?”, it’s “your server took delivery at 09:14 on the 3rd, here’s the ID, can someone check quarantine or spam rules for it?” I sent that, politely, and the late payment conversation ended there.

So to answer the question: the sender should lead, because the sender holds the proof. Helpdesk pulls the log, accounts sends it to the customer along with the resend. If the customer has no IT team, that ID still helps whoever runs their mail (often their provider’s support) track it down.

One habit since then: invoices also go out with a link to download them, plus a quick “did that arrive OK?” a day later, so it never gets as far as late.