Obfuscated in some way implies that it's reversible, which simply means that it's just going to take a little bit of time to unobfuscate the database--in other words, it's probably not worth it.
Hashing an email address would be pointless because the the email address is no longer usable to do things like, you know, send email to that person. As such, the only real option is to store it in plain text--and that makes the most sense.
Comments
Obfuscated in some way implies that it's reversible, which simply means that it's just going to take a little bit of time to unobfuscate the database--in other words, it's probably not worth it.
Hashing an email address would be pointless because the the email address is no longer usable to do things like, you know, send email to that person. As such, the only real option is to store it in plain text--and that makes the most sense.