FAQ

How can secure email SFLetter.com help me?

Secure email SFLetter.com is used to send text and graphic materials that should not be disclosed to third parties or used for other purposes. It hepls to protect attachments from copying, unauthorized access and distribution

What is the difference between SFLetter.com and other mail services with encryption options?

When you are using email services with encryption, after decryption the recipient can do whatever he/she wants with the received email message and its attachments. The main difference is that the SFLetter.com service restricts the use of the received message: protected emails cannot be forwarded or captured by Print Screen; attachments cannot be opened and printed on another device.

How to recover the password to my account?

Please follow this link.

If you have any troubles please contact support@sfletter.com

How to protect my email from hacking and unauthorized use?

Default emails are sent fully protected - the text of an email message is protected and moved into the attachment together with other attachments, and the message body contains an instruction describing how to open protected documents. If you purchase Premium or Business accounts you can select the way you want to protect your email or send it unprotected.

If you select "Protect the attachments", the text of the email message will be displayed as an ordinary message. The instruction about how a recipient can open a protected document will be placed in the attachment.

Is it necessary for the recipient to register on SFLetter.com?

No, he or she does not need to register a SFLetter.com account. The recipient can receive a protected message with any email service.

How to open a protected email message?

Protected documents can be opened with StarForce Reader, a special protected viewer program, on devices running Windows, Android, iOS, and macOS.

A received email message contains an instruction with a link to download StarForce Reader. It helps you to open the protected message and its attachments.

How does the service work from technical point of view?

The service encrypts an email message while sending. The decryption key for emails is stored on the SFLetter.com server. The unique one-time registration code is embedded in each copy of the encrypted messages that are sent to the recipients. It allows getting the decryption key from SFLetter.com server when a recipient opens an email message at first time. Opening of a protected email message is accompanied with its "binding" to the hardware and software configuration of the recipient's device. StarForce Reader is responsible for obtaining the key, the PC binding and the document decryption. It also provides protection against Print Screen and other screen grabbers while reading the email.

What happens if a recipient forwards a protected email message to a third party?

If a recipient opens a protected email, the one-time registration code is marked as a used one on the SFLetter.com server. As a result, a third party will not be able to get a key to decrypt the document, and an unsuccessful attempt to read will be recorded in the log of actions that is available to the sender ("Opening history" feature).

How to track my emails sent?

Sent emails can be tracked with "Email opening history" feature that is available for every protected email message and attachment. The first successful reading of an email message and subsequent unsuccessful attempts to read it on other devices are stored in the log of actions of "Email opening history" feature which can be seen from the Sent folder.

Can I send unprotected emails if I have a Basic account (free)

We created SFLetter.com as a service to send protected emails and attachments with an option to track their opening. Sending of usual unprotected emails never was a target for this service and that is why we have moved this functionality to Premium and Business accounts. But users still can get unprotected emails even over IMAP.

What will happen with my mailbox when Premium subscription stops?

You will not be able to use additional features such as access revoke and time limited access. Also there might be a problem with inbox emails if the size of stored correspondence exceeds 500 MB. You will not get new emails because there is no room for them. It’s better to delete all unnecessary emails to provide storage facilities for new inbox and outbox emails. The service does not delete emails automatically after Premium subscription stops.

What will happen with my mailbox when Business subscription stops?

Your mailbox will be blocked until you prolong your subscription.

How does the service perform the revocation of access?

When a recipient clicks to open a protected document, StarForce Reader that is installed on the recipient’s device asks the server for approved access. If access is granted the documents is opened. During the work with the document, StarForce Reader asks the server every 5 minutes. And if it turns out that access is revoked the recipient gets a relevant message and the document will be closed. The sender can’t reopen the access after revocation. In that case he needs to send an email again. To learn more about this feature please follow the link. The function of access revocation may fail if the sender has allowed offline viewing.

What viewing offline means?

It means that a recipient can open a protected PDF document without internet connection. In free account it is allowed for every email. In Premium account a sender can select what he prefers. We recommend to allow offline viewing with caution because it decreases control level and there may be problems with time limited access and access revocation. To learn more about this feature please follow the link.

Are there any other payment methods besides PayPal?

For now we accept payments only via PayPal. But we are open to your proposals.

What will happen if I send a protected document to computers running Linux? Will it remain protected?

Unfortunately, Linux users will not be able to open a protected document, but it will remain protected. In this case, we recommend you to use Wine or other systems to work with Windows-based applications.

Can I connect my existing electronic mailbox (Yandex, Google, Hotmail, etc.) to SFLetter.com account?

To use the service you need to create a new SFLetter.com account, which cannot be synchronized or merged with other email services.

Can I use IMAP and POP protocols to connect SFLetter.com?

Yes, you can use IMAP. Details are here

Can I send protected emails via my email client, using SMTP?

Yes, you can use your usual email client to send protected emails via SMTP. To make your email protected please add [p] (letter p with square brackets) into the subject line. If you would like to protect only attachments add [pa].

What difficulties can I face while opening the protected documents on a Windows PC?

Administrator rights are required to install StarForce Reader on the device.

In addition, we are constantly updating the program to improve the level of tamper resistance and to expand the supported functionality. This is reflected in the release of new updates. The link to the latest version of StarForce Reader is always available in the instructions attached to every protected email message.

Can I save a protected email message and its attachments to my device?

The email message and its attachments can be saved, but they can be opened only on the recipient's device.

How to print a protected email message?

A protected email message and its attachments cannot be printed.

What are the restrictions for a free account?

Email box size is limited to 500MB.

Total number of recipients for one message cannot be more than five.

Only protected emails sending.

The following restrictions apply to the protection of attachments:

• Protection of not more than two attachments for one email message.
• Protection of PDF and JPG files only.
• The size of an attachment is limited to 5MB.

What are the restrictions for a Premium account?

Email box size is limited to 200GB.

Total number of recipients is unlimited.

The following restrictions apply to the protection of attachments:

• The number of attachments for one email message is unlimited.
• Protection for PDF, JPEG, DOC(X), XLS(X), RTF, PNG, and GIF files.
• The size of an attachment is limited to 10MB.

What are the restrictions for a Business account?

Email box size is limited to 200GB.

Total number of recipients is unlimited.

The following restrictions apply to the protection of attachments:

• The number of attachments for one email message is unlimited.
• Protection for PDF, JPEG, DOC(X), XLS(X), RTF, PNG, and GIF files.
• The size of an attachment is limited to 10MB.

What operating systems are supported by SFLetter.com?

Creating, sending and receiving are available on any device with Internet access.

To open a protected file, please use a devices running Windows, Android, iOS, and macOS.

Which file formats can be attached and protected?

For a free account: PDF, JPEG.

For Premium and Business accounts: PDF, DOC(X), XLS(X), RTF, JPEG, PNG, and GIF.

Other files you can also protect by converting them into the one of supported file formats.

What is the maximum size of attached documents?

For a free account: the sender can attach only two files to an email message, each of which shall not exceed 5MB.

For Premium and Business accounts: the sender can attach unlimited number of files to an email message, each of which shall not exceed 10MB.

When I try to open a protected document, StarForce Reader throws an error "This program can not run while process ONENOTEM.EXE (Microsoft OneNote) is executing. Close this process and restart application". What should I do?

Running of OneNote along with protected files is prohibited, because StarForce Content provides protection against grabbers (programs to capture videos or screenshots from the screen).

In this case, you should disable Microsoft OneNote, which allows you to make a screen capture, to launch StarForce Reader.

How to close Microsoft OneNote:

1. Open the area by clicking on the icon in the shape of a triangle in the lower right corner of the taskbar.

2. Select the Microsoft OneNote icon in the expanded list (purple letter "N").

3. Right-click on the Microsoft OneNote icon and select "Close".