Mail links seem like a house of cards to me. It must rely on a proprietary database and addressing mechanism to work, and both are “maintained” by Apple.
This might be an “out there” suggestion, but is there a way to link to web mail? I suspect it might be more work, but it would address the house of cards aspect, in that there is a canonical addressing system in HTTP URLs that surely even Apple can’t break.
I have no idea, as the link from the task to the particular mail is not visible so the nature of it is hidden (could also be a Spotlight index reference so that would be local to each individual device) 
Definitely not for the faint of heart, it’s an intrepid power move.
But I thought that, if you ever decide to drop Reminders for OF this procedure could be a last resort method, if that solves your issue then you can reassess. If the existing Reminders stop working, well, OF is there!
That begs an additional question you could check out… once a Reminder points to the wrong email, does it point to the same wrong email in all your devices?
I could. I’ve not yet tried to verify if this occurs with just one account or all three. I seldom use links from emails to Reminders from the two personal email accounts (gmail and iCloud). The vast majority of the time the linking is from my work Google email account to Reminders. I could, therefore, copy and paste the URL from the browser to Reminders but I hate processing email in the browser. I much prefer using Mail. That said, I will give that a go to see if it makes a difference. Thanks for the suggestion.
Link Reminders directly with webmail? Not that I know of. There are 100 task management apps that work with gmail but I have no idea if any would work for you. It appears that Todoist might but I’ve never used it.
My needs are simple so I use Google Tasks which links to mail both in the browser and iOS.
Good thought. I don’t know but the next time I encounter the error I’ll check, thanks!
Good questions. I do have multiple accounts (two personal: Gmail and iCloud) and one professional (Gmail). I’ll need see if the problem is related to one account or all.
Well, I am finding that Reminders sync between my Mac and my phone in some cases is similar in slowness as OF. Almost an immediate sync between iOS devices (phone, iPad). Frustrating. I think I am going to keep OF and Reminders concurrently for awhile.
I think I am going to keep OF and Reminders concurrently for awhile.
That is what I’m doing.
Something to consider. Once you archive an email, it is limited by the number of messages you can store in All Mail via IMAP. I used to find with OF that I would link to a mail that was number more than 1000 messages older and it wouldn’t find it.
As a work around, I created an “Archived Mail” folder, so that my archived mail would would be only archives and not get clogged up with All Mail which included everything.
Since I have done that, I have had zero problems with using Mail and Reminders. I waffled between being a purist and using Reminders, and getting sucked into features I don’t need except for Quick Entry. That said, this solved a lot of problems for me, even getting the email from Apple Mail into OmniFocus because mail appends the message GID when you forward it. Probably worth a try which you could do simply by creating that folder and dragging the message you are referring to into it. Make sure that you set the IMAP settings in Gmail appropriately.
That’s intriguing. I do archive to All Mail because the primary account in question is a work Gmail account. However, most of the time, I’m trying to link to messages from the Sent folder. I admit, this is clunky to OF or Things, both of which have the ability to bcc and email to their respective inboxes. With Reminders, I have to send the message, navigate to the sent folder, then select the subject, and then share it with Reminders.
Thanks for the tip; I’ll do some experimenting. It is much appreciated!
With a similar corporate setup, I’ve found the best solution is to use MS To-Do, as, at least for our O365 setup, those two will link when you flag an email or create a task from an email. I now use Todo/Outlook for work and reminders for personal.
I surrender! 
After several months of using Reminders and OmniFocus (OF) simultaneously, I’m forced to abandon Reminders and go with OF. Here’s why:
Despite my efforts, the linking issue persists. For example, I created a reminder this morning from an email, but when I clicked on the link this afternoon, it redirected me to a completely unrelated email from 2020! It’s surprising that Apple, with its massive investments in projects like driverless cars and Vision Pro, hasn’t yet perfected the linking between its own apps.
So, I’m transitioning back to OmniFocus. Fortunately, since I’ve been using Reminders and OF side by side, no extra work is involved.
Just out of curiosity is that happening when you create and access the link on the same computer? For me it happens particularly when I create the reminder link on one platform (MacOS for example) and then try to access the email on another (iPadOS).
I find that the links in OmniFocus made when I forward the email to OmniFocus Dropbox are more robust than the ones that seem to be created with reminders. So I’ve also switched back to OmniFocus.
And, now that OF4 has tags rather than contexts, I seem to be making much better use of them to organize work. (Multiple tags on a task make more sense to me than multiple contexts did - and that means I can bring the same task up in conversation with multiple staff members as appropriate.)
You’re right; Things will automatically copy the email in a to-do. I didn’t realize it had that ability; now I’ll use it all the time. 
Thanks for the tip. And it would definitely solve the issue Bmosbacker and others have. I’ve considered moving from Things to Reminders, but that bug would keep me from doing so. I don’t need the complexity of OF.
I don’t either but I do “need” either smart list or perspectives, neither of which Things offers, otherwise, I’d probably use Things.
It is happening on the same computer, my MBP. When it works, it works across the devices, when it doesn’t, it doesn’t work anywhere correctly. It is frustrating and inexplicable as to why Apple can’t get this work reliability between its apps and devices. Other apps I’m using or have used are able to provide reliable syncing of links, e.g., DEVONthink, Scrivener, Obsidian, Ulysses, et al.
That’s a serious bug you’re experiencing, one that makes it where you can’t trust your system.
In regard to Things, it hits my sweet spot of not doing more than I need it to, or less than I need it to. But your needs are not mine, and of course you need to find a task manager with the features you require. 
I’d prefer to use Things over OF. Unfortunately and inextricably, Things does not have smart lists or Perspectives. I use this feature extensively.
I really like Things and used it for years, but not being able to mark off a reoccurring reminder early without jumping through hoops is a dealbreaker for me now. It should be simple, like it is in every other task manager. (Except MS Todo, which seems to break the repeating part if you mark off something early.)
The good thing about OF, is it can be advanced or as simple as you need it to be. I don’t do anything complicated with it, but it’s incredibly easy to use once you get past the initial learning curve.
