Mailto not working properly

When i click on a Mailto link in firefox, eM Client opens, but no new message window opens.

First suggest to try setting another browser as default eg: Chrome, to make sure it’s not an issue with a Firefox. Restart your computer after setting a different browser default & then see if it works.

Next if setting another browser as default makes no difference, then could be the default mailer MAILTo: hasn’t been selected in the OS settings.

Eg: If you have Windows 10 or 11, check the following post by @Gary below on how to set eM Client default for MAILTo: links.

Apart from that let us know what version of eM Client you have, and if you have Windows or Mac.