Windows 10 little conflict

eM Client reports that it is not the default mail application, but setting the default Windows 10 is fine and eM Client is the default

Hello Raul, when exactly are you seeing the error/warning that eM Client is not setup as the default mail application? Can you please check your control panel settings and check if mail handling options are all setup for eM Client. What version of eM Client are you currently using on your computer, can you please check the exact release number in Help > About?

Thank you,

I have the same problema. Applications ( explorer, FileMaker, etc… ) cannot do “mailto” … It seems like System doesnt put as default emclient… But I set it.

I’m seeing this behavior within Windows 7 Ultimate for a long time now, however, I didn’t bother about it. Perhaps it has to do with a previously parallel installation of Thunderbird for backup and emClient. Don’t use Win10 at the moment.

Will have to check the system settings as pointed out by Paul though.

Hello, is there any prompt thrown by MS Edge or any errors displayed when you click on a mailto link in your browser?

Please make sure that .NET 3.5 is present in your Windows 10 installation as it includes some system components that can be vital for some of the eM Client’s features, amongst them the mailto/send to recipient sMAPI features. To check if the installation is present, please navigate to Control Panel > Programs and Features > Turn Windows features on or off.

Hope this helps,

I saw and it was installed already, and no Works.

Please make sure that the application is setup as default or make a screenshot of any error messages you’re seeing while using mailto function from the browser. I’m unfortunately unable to replicate the issue, the new Windows will prompt about switching applications and can open a new mail from eM Client without any issues.


Please look at this.

I did it, but still have the error. Look at image.

Not quite sure, what is this referring to, when do you see this error? Does this appear after using a send to option in an external application? Do you have .NET 3.5 enabled in your Windows 10 installation?


Yes, after using “send To” in an external app.
Yes, I have .net 3.5 in windows 10

Please open Parameters in Windows 10
Select System
Select Default Applications
Click Electronic Mail
From the list select eM Client !!
That’s all

I did it before… same error …

Hello again, are you able to send messages from the windows built in “Send to recipient”? Right click an item on your computer, for example a document on your desktop and select the option - check if the application opens and attaches the file to attachments. Please note that eM Client includes a support for the “Send to recipient” option over the sMAPI program interface, unfortunately some external apps may not support this and can force opening the message over MAPI or a different interface, in that case it may not be possible to use the option with eM Client.

However the system control should work if all was setup as default and .NET 3.5 is present on your windows installation.



I did it with left menu bottom of mouse, I send a file… All was ok.
I have another computer and all runs correctly with emClient. All same, windows 10, FileMaker , etc…

I’m afraid this means the application is using an unsupported program interface and that it may not be possible to send data to eM Client through this specific application.


no, no, the app is running in another PC with win10 and emclient.
The probem is maybe something wrong with installation or own win 10.
I think .Net Is corrupted or something like that. Anyway if there is any idea, let me know before I format PC again. Thanks.

I like a lot emclient but as i said before cannot send emails with attachment from others app. A lot of issues… I am sad. I tested it under win 8.1 and same trouble as win 10. Anyway if you have .NET 3.5… the same trouble. I hope you can resolve it asap. Thanks.

Hello Joan, I’m sorry, but if you’re able to send out data through the “Send to recipient” option on your windows, when for example sharing a file on your computer to the default applications, but you’re unable to send out from other applications using this feature - I’m afraid it is not an application, but more likely a system issue.

But as I suggested, the option needs to support sMAPI program interface otherwise it won’t be possible to include your application data in a file in new eM Client message.


I can confirm that with .NET Framework 3.5 all is now working fine!
Best regards, ste