Domain aliases & Google


I have 3 domains, one .com, one .es and one

Right now I am using domain aliases but I have read that google won’t index the 3. What is the best way to get the 3 indexed??

In the future the problem will be only with 2, as 1 of them will have a different language and therefore different context.

Many thanks

you dont want them indexed.
copies are penalized. an alias is sort of a copy as it is a different url but with "same content" for a bot.

seo the main site, use a sitemap and then indexing can still take a lot of time.