This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox 91.0 and Mailto Link message on Outlook on the Web

  • 4 replies
  • 1 has this problem
  • 1 view
  • Last reply by Gotadimple

more options

With the upgrade to v.91.0 the following message appears on the web page for Outlook on the Web:

Add "outlook.live.com" as an application for mailto links

What are mailto links? Why would I want them? How can I disable seeing this message?

 Rita
With the upgrade to v.91.0 the following message appears on the web page for Outlook on the Web: Add "outlook.live.com" as an application for mailto links What are mailto links? Why would I want them? How can I disable seeing this message? Rita

Chosen solution

Gotadimple said

So, what application will I be adding to my system if I say yes? And what does it do? And if I don't want how does a user turn off this message????

Adding the "application" actually adds a couple of lines to a configuration file named handlers.json which is consulted when Firefox needs to know how to open a link with a protocol it doesn't handle itself, such as mailto: or zoommtg:. I have attached a screenshot showing where that goes and what it looks like for the one offered by Outlook.

The bar stops appearing if the offered mailto handler is already saved. However, if you decide you do not want to save it -- because you never ever want to open a mailto link in Firefox directly into Outlook online -- I am not aware of a way to prevent the bar from appearing. With some bars, using the little X on the right will be "remembered" for future visits, but I assume you already tied that?

Read this answer in context 👍 0

All Replies (5)

more options

That is a reference to a setting on the General page of Settings/Options (see screenshot).

more options

Thanks for your reply and screenshot. Unfortunately, that didn't work because my Mailto Setting in Firefox is set to Mail (default). As I test, I went into Windows Settings/Apps/ Default Apps and changed the Mail default from Windows 10 to Outlook. Now the message is a bit more specific (see the screenshot).

So, what application will I be adding to my system if I say yes? And what does it do? And if I don't want how does a user turn off this message????

more options

Chosen Solution

Gotadimple said

So, what application will I be adding to my system if I say yes? And what does it do? And if I don't want how does a user turn off this message????

Adding the "application" actually adds a couple of lines to a configuration file named handlers.json which is consulted when Firefox needs to know how to open a link with a protocol it doesn't handle itself, such as mailto: or zoommtg:. I have attached a screenshot showing where that goes and what it looks like for the one offered by Outlook.

The bar stops appearing if the offered mailto handler is already saved. However, if you decide you do not want to save it -- because you never ever want to open a mailto link in Firefox directly into Outlook online -- I am not aware of a way to prevent the bar from appearing. With some bars, using the little X on the right will be "remembered" for future visits, but I assume you already tied that?

more options

You are correct, the "X" on the bar removes the message. But then it shows up the next day when I start up my system. So you have talked me into it. I'll click on the button. Also marking this as solved.

more options

Hey guys! I may have had the same issue and found a really neat and helpful answer at Superuser .com to attempt in about:config :

"This recently just happened to me, after over 15 years of using it. Changing network.protocol-handler.external.mailto to false seems to have worked for me. – Asinine. Sep 21 '20 at 21:12" --> https://superuser.com/questions/363827/how-can-i-disable-add-application-for-mailto-links-bar-in-firefox

WARNING: Changing preferences through this interface not officially supported Hidden settings edited using the about:config tool are explicitly not supported, which means that Mozilla makes no guarantees they will be supported in the future, or that Mozilla will fix them if they break. Mozilla does not test these preferences, and will not in the future. That includes security and performance testing which these preferences may affect.

Here is hope it helps! Cheers!

[Warning added by moderator.]

Modified by Chris Ilias