If running Gnome, Hyperland and want to use Mailspring, modify: /usr/share/applications/Mailspring.desktop to use gnome-libsecret change line:

Exec=mailspring %U

to:

Exec=mailspring --password-store="gnome-libsecret" %U

File may looks something like:

[Desktop Entry]
Name=Mailspring
Comment=The best email app for people and teams at work
GenericName=Mail Client
Exec=mailspring --password-store="gnome-libsecret" %U
Icon=mailspring
Type=Application
...