If you use GMail for your email, you may have seen the opportunities in GMail Settings, which let you manage and use multiple email accounts.
GMail lets you use both GMail, and non GMail, email accounts from one - or from different - GMail desktops. This lets you manage multiple email identities from one single GMail account - and gives you opportunities to cause yourself various problems.
Both problems with account / blog recovery, and email delivery oddities because of addressing confusion, can result from the ability to mix and match email addresses and email desktops.
GMail provides two Settings tabs - "Accounts and Import", and "Forwarding and POP/IMAP", which let you manage and use multiple email accounts, from one GMail desktop. It's likely that other, complementary email delivery services have similar options.
"Accounts and Import" lets you use multiple identities when sending email. "Forwarding and POP/IMAP" lets you automatically transfer email, from account to account. You can use your GMail account to either "pull" / retrieve email from any compatible email account (GMail or non GMail), or "push"/ send email into any compatible email account (GMail or non GMail), in an ongoing basis.
Using both options together, you have considerable ability to use multiple email accounts from one desktop, transparently. Like the many problems with having multiple Blogger accounts, forgetting any multiple EMail account setup can leave you with worse problems.
When you need to recover access to your Blogger account or blog, you are advised to search every email account, thoroughly, for important email. As part of a thorough search, you may be smart to also check the Settings - "Accounts and Import" and "Forwarding and POP/IMAP", for each email account being searched - if you ever use multiple account management options, with either GMail or any non GMail system.
Failure to remember past use of either account import or automatic forwarding, as part of your email account management procedures, could leave you with ongoing problems with either account / blog recovery, or addressing confusion.
An Important Update
If you did not use a Blogger / Google account when you Followed this blog, years ago, you are probably not Following now . During the past...