public async Task OnNextAsync(UserRegisteredEvent item, StreamSequenceToken token = null)
        {
            var @event = new UserVerificationEvent()
            {
                Email  = item.Email,
                Status = UserVerificationStatusEnum.Verified
            };

            if (_verificationState.State.IsAlreadyVerified)
            {
                @event.Status = UserVerificationStatusEnum.Duplicate;
            }

            if (_blacklistedEmails.Get().Contains(item.Email))
            {
                @event.Status = UserVerificationStatusEnum.Blocked;

                _logger.LogWarning("Blacklisted user {email}", item.Email);
            }

            await _userVerificationStream.OnNextAsync(@event);

            _verificationState.State.IsAlreadyVerified = true;
            await _verificationState.WriteStateAsync();
        }