I think the humour at the start might have been enough to make many people not read the email TBH. Something a little less tongue-in-cheek and simply nice/approachable is likely to net a better chance of response.
You don't describe the business problem, but go into incredible detail about technical details that either nobody reading the email[1] cares about.
Even more than that - you're basically asking them to run random bash commands from the internet.
They shouldn't trust your advice, anything you say would have to be verified by their own team, so the level of technical info is useless to them. In fact, including all the technobabble mnakes it look even more like a scam.
Remember, not that long ago it was a common scam to ask employees to make changes to the phone system, which would give the scammer free international calls. Your email is idenitical[2] to one of those scams.
A better email would be (and this isn't perfect):
"Hello, I am a recent customer of yours and noticed that all your confirmation emails aren't being sent properly and won't be delivered at all for most users.
I'm a sysadmin, so had a look at the the problem using public data, and it looks like your tech team overlooked a setting when they set up your email system. Its a easy mistake to make and would take them 5 minutes to fix.
The technical details are that there is an "SPF" record which says who is allowed to send emails as your company - this is correctly set up for your office emails through outlook, but not set up for the automated emails from shopify.
If you let your tech team know that shopify is missing from the SPF records, and they'll quickly see the issue and fix it within minutes.
If you would like more information about the issue, I'd be happy to advise further[3]"
[1] The people who do care won't see your email. [2] To the untrained user. [3] I mean, I wouldn't, but you seem like you would ;)
RE: random bash commands. Part of the reason I linked shopify's SPF page to them -- an attempt to provide external validation.
But I get it. Which is why, as I mention in that other response, it doesn't matter what I send. Even pleas to forward to a technical person = ignored.
(I bet lots of tech people get forwarded all sorts of crap that IS a scam, so yell "DON'T FORWARD THIS STUFF TO ME".)
In fact, I have even called some places. One started screaming at me. I'm guessing some phone scam "got them", and therefore equated me to the same.
What can you do?
I mean, seriously?
If you respond to that without technical data, then you're basically saying "No, I did not receive it", and their response is "Your gmail lost it" (because mail = gmail).
The problem is that emails sent with "I didn't get the confirm email" are immediately thought to be "user error". And you know what?
99.9999% of the time, they surely are. Bad email providers, lost in SPAM folders, even missed in INBOX.
So if you don't include tech info, you're stuck in this category, else many exchanges back and forth.
Because once I then respond with technical info?
You get the same glassy-eyed type of incomprehension, with often zero response. Or a response that invites another 5 back and forths, with the other side upset, because now they feel ignorant.
I feel there really is no proper answer here... except, I still have to try. :P
I've started emails off with (very close to):
"NOTE: this is a technical issue. You may not understand it. Please forward to a technical person", with a lot of variety on that line.
These too garner little response.
I've started out with problem first, then tech info. It seems to matter little, and my humour via that first line, was an attempt to amuse non-technical types into reading further.
I must have concocted > 100 over the years. Perhaps 10% responded, regardless of the layout or form of the email. Even 10% is generous.
The reality? Anything technical, no matter how presented, is too confusing for many.
'I have found a problem. The problem has this negative impact. Brief description of problem.'
Be serious if you want to be taken seriously, especially in your initial communication with an unknown third-party.