iOS Deep Link to Open Specific Email in Outlook App

I cannot believe that the day on which I’m finally able to write this blog post has finally come. I’m not exaggerating. I have been trying to solve this and find a way to open specific emails (using the message id) in Outlook for more than five years.

This may seem like a very small thing to most but to me, this is really big. And based on various forum posts online, I know that other people were looking for a way to do this as well. Of course, one of these forum posts is from myself, from 4 years and 9 months ago.

When ChatGPT was released, I tried to search for a solution again but all that happened was that I was let down by an over confident AI generated answer that turned out to do exactly nothing for me.

So, today, I felt like it’s time to try my luck again. I guess if I had a middle name, it would be Determination. I found this other Stack Overflow post, on which I apparently also commented coincidentally exactly (on the day) 1 year ago!

Can you please try to decompile the Microsoft To Do APK? If an email is flagged and there’s a task for it in To Do Flagged Emails, there’s a button to open the email in Outlook. I think To Do holds the answer how you can open an Email by id in Outlook…
― Myself

The next thing I know was that I downloaded the To Do APK, decompiled it using an online tool and when I searched for ms-outlook:// I found this line:

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(Uri.parse("ms-outlook://emails/message/open?restID=" + str + "&immutableID=" + str2 + "&account=" + str3))

There you have it Ladies and Gentlemen, this is how you link to a specific email using the message id in Outlook on iOS.

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ms-outlook://emails/message/open?restID=<messageId>

Now I can finally link to an email and open it directly in Outlook on iOS from wherever I want. I mostly use this for notifications sent through Power Automate but it works from any app which supports links.

iOS Deep Link for Specific Email in Power Automate Open Specific Email Demo

For what it’s worth, this is much easier with the iOS stock Mail app. There you just have to create a link with message:<messageId>. But of course it’s much nicer to directly open the email in Outlook as many companies don’t allow anything else than Outlook.

I haven’t tested this on Android but given that I got the link from the APK, I’m quite sure that this will work on Android as well.

I hope this made your day as well!