The queue probably got cleared when the postfix container was recreated as it's spool directories weren't attached to a persistent volume .
Probably the easiest would be to manually set email_verified to true in the local_user
table for those users (basically assume the email addresses were correct).
I don't think there's a way to re-trigger the email verification without going through the sign-up process, so your option #3 is likely what you'll need to do.
You could do one of the following if you don't want to blanket-allow the existing signups:
Option 1: Go into the email_verification
table and get the email and local user ID to look up the account and send the verification token manually to them using the email account you configured with Lemmy:
Subject: Verify your email address for {your-domain}
Please click the link below to verify your email address for the account @{username@your-domain}. Ignore this email if the account isn't yours.
, [Verify your email](https://{your-lemmy-domain}/verify_email/{verification_token})
Option 2: Note the username and email address from the local_user and person tables, delete those, and recreate the accounts for them. They'll have to reset their passwords since you'll have to set one on their behalf, but that should be manageable. Just make sure the password you set for them is completely random, complex, and very long (not sure if the length is still 60 characters or not).
Option 3: Delete the records as in option 2 but send them an out-of-band email from your Lemmy address saying they'll need to re-register.