That isn't the point, if they can send it in plaintext then they have it in a recoverable form. They shouldn't be storing your password at all. They should be storing a hash of your password.

And on top of all that, sending it plaintext via email, itself a largely open format, means they've broadcast it to all kinds of other potentially bad actors.

Plus it indicates (to me) a questionable grasp of security, not a great sign for a VPN provider.

Its just wrong.