I work for a company and one of our clients has e-mail that is literally disappearing. For the most part, their inbound and outbound e-mail works just fine. However, from time to time, an e-mail coming in will up and disappear.
For example, G sent an e-mail to H from his work e-mail. H then replies to G’s work e-mail and personal e-mail. The personal e-mail receives the message on schedule, unchanged, but G’s work e-mail never receives the message. H will not get a message saying that G’s work mail didn’t get the message. By all accounts, if G didn’t have his personal e-mail, he would never know that the message was sent.
By checking mail server logs, we can see that H’s message to G didn’t get blocked or deleted. The server doesn’t even show it coming in. We also know that H has sent mail to us in the past and indeed, some of this mail gets through still. H isn’t the only person having this problem on the outside and G isn’t the only employee having this problem on the inside.
So, to recap, only outbound e-mail is 100% while inbound is roughly 95%(although it could be lower) and we have no warnings or notifications (from either side) that there was a problem or an error.
I run an email server and this has happened to us, too. Logs show everything is normal and no one got any postmaster notices.
Turns out it WAS getting deleted by our server without notice on the log and we are just idiots. Hunting down and changing some spam settings are what fixed the problem.
I would check again and again and again until you find the settings that might be causing mail to be deleted instead of bounced or flagged.
What mail server software do you use? I use IMail fwiw.
well, we thought it might have been a spam e-mail filter but we checked and we don’t have anything being deleted by the spam filter. It simply marks the e-mail as spam and continues it to the in box or trashcan. (Don’t worry, we checked the trash can!)
We’re using a Nitix Blue server using Domino as our mail and DAMO as our client to connect to Outlook, I believe.
Is it possible you have some type of content filtering on a firewall/intrustion detection system (in front of the mail server)? Our firewall has built-in IDS that will block incoming and outgoing traffic based on content inspection, and I believe by default it doesn’t notify anybody. I think we had to set it up to send us alerts when it blocks something.
I don’t think it’s ever blocked any email, though.
Here’s a question: does there seem to be any relationship between the emails that go missing and whether or not those emails have attachments? Or to put it another way, do plain-text-only emails ever disappear?
First, you need to check your DNS MX records - these are what tell other people where to send your email. You probably have a primary (your email server). You could have a secondary MX record (which should collect mail when the primary is unavailable). You could have a problem where the mail ends up on the secondary but never passes it on.
You also need to check the inbound mail path - how does the mail get through the firewall - could there be a content filter that someone has forgotten, or a mail forwarder that is not working properly.
Shows what I know. I thought it was impossible. I recently read a novel where an email disappears from someone’s inbox after she had read it, and I thought that it was a ridiculous plot point that everybody knows would never happen in real life.
Huh.
If anyone’s wondering, the novel was Monkeewrench.
No, you’re right. Once it’s in your mailbox, it’s not going away without user actions or malicious software. But a misconfigured mail server can drop messages on the floor instead of transmitting them or bouncing them back to the sender.
I’m not sure I’d quite class it as malicious, but I’ve heard of ways that a selkf-destructing email can be sent (although I don’t think the message itself disappears, just the content - which isn’t sent, it’s external content that is embedded )
We have sent both e-mails with attachments, e-mails with out, some plain text, some html encoded. It seems to drop them at random as some will get through and others won’t of the same type.
We checked the firewall and don’t see anything being blocked. We contacted the manufacturer in Canada and he remote accessed into our server. Spent several hours looking around and examining logs and could find nothing on the server side that would be preventing this.
We are currently checking our DNS MX records to make sure that everything is assigned correctly but I don’t know if that is going to be it. It just seems weird that some emails from an individual will come in but not all. Regardless of the content.