Transactional email classification disregards Subscriber’s status. A Subscriber does not need to be Active to receive transactional emails. However, the status Held prevents from sending even a transactional message to a held Subscriber.
Find Held Subscribers and Reactivate
Sometimes it is a single request, and incident reported or a maintenance. Find such Subscriber(s) and update their Status.
SELECT
Status,
SubscriberKey,
EmailAddress,
DateJoined,
SubscriberType,
Locale,
BounceCount,
DateUndeliverable
FROM _Subscribers
WHERE Status = 'Held'