[fda5b]

Well, the OPSEC Everyone says it is easy to understand and difficult to apply. To begin with, why accounts created before this year are surely affected by one or another leak. Okay, then to get digital cleaning in the situation of a loss of control of an email account.

What can be done? As well as other suggestions.

[logan0]

use unique long passwords for each account

[fda5b]

That is not possible when control of the account has already been lost. Some solution for these cases, other suggestions will be well received as well.

[Quark]

You need to assume the worst:
- Someone has already fetched all e-mail
- Someone has already reset all passwords

Identify the most critical services tied to that account, and try to contact them and see if you can regain access by identifying yourself by other means than this e-mail account. Use social engineering tactics and explain the situation. You might not succeed with all accounts, but its better than nothing.

As for the future? Multi-factor authentication, passwordless, hardware tokens etc.

[fda5b]

As always, the worst is taken by those who have mail services that are no longer active. Therefore, many times they cannot verify the ownership of their account or simply the service does not allow it.