What is the earliest date on which a message, deleted and removed from Trash, will no longer be searchable in Vault if it was sent on January 1 and the retention rule lasts 30 days?

The correct answer is based on the retention policy applied to messages in Google Vault and the lifecycle of the messages deleted and removed from the Trash. When a message is deleted from the inbox and subsequently removed from the Trash, it remains subject to the retention rule governing its retention duration.

Given that the retention rule lasts for 30 days, this means that from the date of the message (January 1), the message will continue to be stored and searchable in Vault for a full 30 days. The retention period starts immediately upon deletion and continues up until the end of that timeframe.

Counting 30 days from January 1 brings us to January 31; however, because the retention period lasts until the end of that 30-day period, the message will actually still be searchable until January 31. Therefore, it will no longer be searchable on February 1.

Thus, the earliest date on which the message will no longer be searchable in Vault is February 1, which is why this option is correct.