Lack of interest Store email addresses more efficiently

[AlexT]

Split from here.

In the database, you could store users's email domain names separately from the email address and refer to them by index. This could potentially save a lot of disk space (since we're talking about avoiding overhead) for forums with a larger user base, given that the majority of users use one of the few available public email providers. See here for an example:

http://www.mssqltips.com/sqlservertip/2657/storing-email-addresses-more-efficiently-in-sql-server/

 

[Alpha1]

That could also cater to white-listing and blacklisting email domains.
I only allow white-listed email domains and if a user registers with a new email domain then my moderators will have to review the domain, and whitelist/blacklist the domain. This works great to keep block fake email domains and highly problematic spam domains.