|Missing Emails, Where Are They Going?|
I'm no novice to email.
Let me preface this with I used to build an email product in the early '90s for Lotus, I'm very familiar with email gateways and such, fairly well versed on the latest email technology too, so for me to post this means I'm severely stumped.
Here's the situation, I send out auto-response emails to member actions on my server that seem to vaporize every now and then for no reason.
Not too frequently, maybe a handful every month, but just enough emails have trouble being vaporized to lend credibility issues to my service with new customers.
My site isn't in any DNSBL, I have SPF enabled, and I warn people in big bold red letters to "CHECK YOUR SPAM FOLDER".
My email servers are very efficient, delivery is typically less than a couple of seconds from the order being placed or account registration to delivery in their inbox.
However, with everything running top notch and squeaky clean, every now and then I get contacted by someone claiming they didn't get their order receipt or account creation notification.
I check the email queue and it's always empty, they all clear, unless someone makes a typo and it's bouncing.
Customers always claim they checked the spam folder like I suggested and it's simply not there.
Doesn't seem to be anything in common when this happens either, like a common host or anything like that.
Here's the other odd thing, once they contact us directly via our "contact us" form and we email them directly, %99.9999 of the customers seem to get our direct emails.
Anyone have any possible ideas as this problem is driving me nuts!
I've seen that too a few times.
Are order receipts, account creation notifications, and responses from the contact us form all coming from the same e-mail address? (I've seen cases where email@example.com might be blocked, but firstname.lastname@example.org isn't.)
What if them made a typo, but it's not bouncing? For example, they are email@example.com, but they fat fingered it as firstname.lastname@example.org, which also happens to be a valid e-mail account there.
Another possibility is that they simply accidentally deleted the e-mail and didn't remember deleting it (maybe they had a bunch of spam messages delivered around the same time).
Oh, and I've seen cases where the message was delivered to their server, their server's spam trap ate it, but apparently it didn't digest well because future messages went through fine. (The sysops could have been tweaking their filters when the first message tried to go through.)
They're all from either support@ or sales@ email addresses, no newsletters.
Also checked for typos, that happens now and then but it's rare that it's the cause and then of course I can simply resend the email.
I think like you said, maybe a badly behaving spam trap, but it would have to repeatedly behave bad to prove that was the problem.