My daughter is having the same problem. Her validation email account is set to her school account. She graduated and left the school some time ago. Now when providing correct master credentials on her laptop, which she always uses to login to lastpass, indicates to check her school accounts mailbox to validate the login. There are no means anymore to access this mailbox as is it closed down.
The support notes which guidance are not helpfull at all in this case. Shall she stop looking to recover her access to lastpass vaut and stop using it.
The only way to get some help is this community, but I doubt that the community can remove the verifcation sending mail.
