To add and set Yahoo! Mail as the default Opera mailto:
handler, the file, webmailproviders.ini must be edited (in 64-bit Windows, this is at C:\Program Files\Opera\defaults
). Make a backup of it first, for safety, and then edit it to also include:
[Yahoo! Mail]
ID=3
URL=http://compose.mail.yahoo.com/?To=%t&Subject=%j
ICON=http://mail.yahoo.com/favicon.ico
Depending on the entries already existing, change the '3'
in the ID=3
line to another number, to avoid it having a duplicate ID. (In my case, ID=3
does not have a duplicate id.)
Then go to Preferences > Advanced > Programs and edit mailto:
in Opera for the action to use a web mail service rather than Open with another application, selecting Yahoo! Mail which should now be in the drop-down list.
Source