You're referring to [this question][1].  And you should be able to see who deleted it, and a reason (if they left one), as it's a post you made.

For what it's worth, it was deleted because it was

1. [Crossposted/reposted from SuperUser][2].
2. Very off topic.
3. An incredibly bad question with no value anyway.


  [1]: https://serverfault.com/questions/434795/get-email-backups-of-any-mail-accounts
  [2]: https://superuser.com/questions/483347/how-to-get-email-backups