With Phase 2: Alignment, we are introducing new features which allow guilds to set their allegiance with other guilds in The Old Republic. Now a guild leader, along with members who have the proper permissions, can select up to three guilds as either Allies or Adversaries, depending on their faction affiliation. Qualifying guilds that are marked as Allies and Adversaries of other guilds will have the highest chance of being placed in the game together, allowing these guilds to coexist on the same server.Now this is more like it, especially being able to spam everyone you know via email to seduce them to the Dark Side. I can see this being a useful feature, although only the guild master can invite people, unless you are an officer I assume.
Another feature being implemented with Phase 2 is the ability for guild leaders and members with the proper permissions to invite friends to join their guild via email. You can start recruiting new members today!
The website does offer a mail form to send emails to your guild leader, but I am reluctant to give someone I don't know in real life emails of people I do, so I may fall back on just emailing people the URL of the guild.