Automatically associate added emails with "other service" default

I've been importing all my previous email associated to Gravatar, however the experience was a bit annoying as I was expecting this to set the previously used image as default for such email, instead of having me to redo the same process for them all (and I had like 8 with different images).

So, please... I like the idea of a free service, but make the migration a nicer experience.