Responding to encrypted email message in free outlook.com (hotmail) account

Question

I received an email from my bank with a document to scan and send back. In the subject line, it reads [Encrypted] with a string of numbers afterward. I was told to fill out a document, scan it in to my computer, and email it back. I was told that if I reply to the original email, the document I send back will be encrypted (even though the free version of Outlook doesn't include encryption). When I hit reply, the encrypted button is still grayed out. I don't know if I am ignorant of how encryption works or if the bank is mistaken. Can the free version of Outlook (Hotmail) send encrypted files? Should the encryption button be grayed out? TIA.

Answer 1

Hi Bruce Geiselman,

Welcome to Microsoft Q&A forum.

With a free Outlook.com/Hotmail account (without a Microsoft 365 subscription), it can be expected that the Encrypt button is greyed out or unavailable, because the available encryption options depend on the account type and whether the account has a qualifying Microsoft 365 subscription.

If you received an email from your bank with a subject like [Encrypted] + a string of numbers, that message has typically already been encrypted/protected by the sender. In this situation, you don’t need (and may not be able) to manually enable Encrypt on a free account. Instead, open the protected message and use Reply/Reply all directly from that message, type your response, attach the scanned file, and send. Replying from the protected message keeps the reply within the protected thread (subject to the sender’s policy).

If your bank specifically requires you to compose a brand-new email and manually choose Encrypt/Do Not Forward (instead of replying within the existing protected message), those options on Outlook.com are typically available only when you have a qualifying Microsoft 365 Personal/Family subscription for your personal Microsoft account.

Because this involves bank documents and sensitive data, it’s recommended to use the bank’s secure submission channels (e.g., an upload portal/online banking task flow) and verify the request through official bank channels before sending scanned documents by email.

Official Microsoft references:

• Error replying to encrypted emails from Outlook Desktop
• Learn about securing and protecting email messages in Outlook

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Answer 2

Outlook.com (the free Hotmail service) can receive and reply to encrypted messages that were protected with Microsoft Purview Message Encryption by the sender (for example, a bank), even if the Outlook.com account itself does not have its own encryption feature enabled.

Key points for this scenario:

1. How the bank’s encryption works
   • The bank encrypts the message before sending it, using Microsoft Purview Message Encryption or a similar protection policy.
   • The encryption is applied on the sender’s side; the recipient does not need a paid encryption add‑on to receive or reply within that protected conversation.
2. What is seen in Outlook.com
   • Encrypted or protected messages may show indicators such as a lock icon or a banner at the top of the message explaining restrictions.
   • For messages encrypted with Microsoft Purview Message Encryption, Outlook should open the message like normal, or provide a link and instructions if using another mail client.
   • The “Encrypt” button in the Outlook.com compose window refers to initiating new encrypted messages from that mailbox. In a free Outlook.com account, that button can be unavailable or grayed out, which is expected.
3. Replying to the bank’s encrypted email
   • When replying to an encrypted message that was sent using Microsoft Purview Message Encryption, the reply is sent back encrypted as part of the same protected conversation, as long as the reply is done using the provided reply flow (Reply/Reply All on that message).
   • The documentation states that if in a Microsoft 365 organization, replies to encrypted messages remain encrypted and an encrypted copy of the reply is sent back. For Outlook.com, when the message is opened via the encrypted-message experience (for example, via the secure portal or Outlook on the web), replying from that experience keeps the protection.
4. Why the Encrypt button is grayed out
   • The grayed‑out Encrypt button in the Outlook.com UI does not affect the ability to reply securely to a message that is already protected by the sender.
   • It only indicates that the Outlook.com account cannot independently start new encrypted messages using that button.
5. Practical guidance
   • Open the bank’s encrypted email using the method provided (directly in Outlook.com or via the secure link/portal if present).
   • Use Reply (or Reply All) from that encrypted message window and attach the scanned document before sending.
   • Do not worry about the Encrypt button being grayed out; the protection is controlled by the original encrypted message and the bank’s policy, not by that button.

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References:

• Open encrypted and protected messages
• Message encryption