Merge gravatar accounts

I accidentally created two different accounts for my two primary e-mail addresses. I would like to join merge these into one account.

I tried deleting one account and adding the mail to the other, but that did not work. It complained that this mail is already associated with an account.
Said account was just disabled not deleted.

There should either be a way to join two accounts or to delete one in such a way that the mail address can be reused in a different account.

The issue names no files, tests, or entry points. Start by locating the account deletion, disabling, and email-association flows, then determine how account merging or releasing an address would fit them. Done should allow two accounts to be joined or let an address from a disabled account be reused without violating existing account rules.

Written by the indexing model from the issue text.