If two users are MeSince users, MeSince has the recipient's public key certificate, and of course, the user does not need to exchange the public key certificate.

If one of them is not MeSince user, as long as the MeSince Certificate Database contains the recipient's public key certificate (no matter who issued it), MeSince will automatically send the encrypted mail to the other user using the recipient's public key certificate, and the other user can decrypt it using any mail client software that supports S/MIME encryption, regardless of whether he/she has used MeSince.

In addition, MeSince supports multiple certificates encryption in the outgoing email, to make sure users can decrypt the encrypted email by using any certificate in hand.

Users who need to send encrypted emails in large quantities can obtain the recipient's public key certificate by calling the MeSince Open Platform API.

In accordance with the S/MIME standard, the email subject is not encrypted. Only the email body (including attachments) is encrypted. Therefore, it is recommended not to write sensitive information in the subject, the original habit of directly writing the core content of the email in the subject needs to be changed. It is recommended that it's enough to only simply mention the email content in the subject, or just write 1-10 to indicate the priority of the email.

When you receive an encrypted email, you can sign in your mailbox on a browser, and if the email is really encrypted, then you cannot browse it, and the message becomes an attachment or simply can't be display. If you view your encrypted messages with other email client software that does not support S/MIME encryption, you will be prompted "cannot open the message or cannot decrypt". If you use Outlook and have imported your encrypting certificate, Outlook can decrypt your encrypted messages correctly.

Someone has used MeSince to send an encrypted voice message to you, and only you can open to listen it in the world, and it can be permanently encrypted and stored in your mailbox. We think that each voice message and short video from your friend and your family is worthy of collection and must be encrypted to protect privacy. Collecting a voice message and short video from your loved ones will be a permanent asset.

MeSince not only encrypt all text message, but also encrypt your voice and video messages. You can tap the recording button on the right side of the subject to record your voice message. This message will be sent as an attachment file to the recipient's email, and Only he/she can open to listen this voice message in the world.

Now, use MeSince to send sweet voice message to him/her, only he/she can listen your voice privately.

Yes. If the recipient does not use MeSince, but he/she sent a signing email to you using other email client, then MeSince can send encrypted email to him/her and he/she can decrypt it using other email client. If this recipient doesn’t have any encrypting certificate, then MeSince will remind you to send an unencrypted plain text email to the recipient that telling the recipient to download and install MeSince to open the encrypted message.

After the encrypting certificate is installed successfully in MeSince Windows version, you can use this certificate in Outlook to decrypt the encrypted email sent by MeSince. For other email client, you need to import the encrypting certificate (but too complex that not recommend).

These icons appear in the received email sent from MeSince and in the interface of writing an email (email sent from other Email client may not display any of them). When clicking an icon, a popup sentence will give you its meaning. The first icon above means that the email is encrypted, and is not possible to be read by any third party; the second icon, indicates that the email has been digitally signed, which ensures that the email has not been tampered; the third icon, indicates that this email sent time is from the trusted time stamp server, which warrants the authenticity and accuracy of the email sending time; the fourth icon, indicates the email sender's validation level is level 1(V1), which means only email is validated.

When you start to write email, the four icons are displayed in default. The first one means you want to send encrypted email, the second icon means you want to sign the email, the third icon means a timestamp signature will be added to the email, and the fourth icon is your current identity validation level. If it is V1, it means only the email is validated, and if it is V2/V3/V4, it means your identity is validated to related level -- Identity Verified and Trusted.

Please also refer to the MeSince UI Icon Meaning for detailed instructions.

Yes. You can send unencrypted email, only by a click on the padlock icons to turn it gray . And you can click the signing icon not to sign the email . Note that settings on the Identity verification icon, Signature icon and Time Stamper icon are synchronous, so if you cancel the signing, both the Identity icon and the Time Stamper icon will turn into gray too.

All emails sent by MeSince are encrypted unless you expressly cancel it. We think that email encryption is significant and only by doing so can your private information and confidential information be protected. However, in consideration of compatibility with other email Client Apps, which do not support digital signature or encryption, we provide the choice to cancel the two functions.

This is because that the certificate you import is issued from a CA that is not currently trusted by MeSince, and MeSince cannot identify the validation level of the certificate. Even so, such type of certificates can still work normally on signing and encrypting email, only the icon that differs.

Icon means this certificate is trusted by OS, but not by MeSince; Icon means this certificate is not trusted by OS and MeSince.

Email content is encrypted, indeed, it protects email contents from any way of stealing in the transmitting process. However, SSL certificate deployed on mail server protects your password for log into your email account. If the mail server is not deployed with a SSL certificate, your password will be transmitted to the server in plain text. Illegal person can steal the password to login your email and then get your email certificate and may be able to decrypt your encrypted emails.

If you have known that your email provider does not have SSL deployed on the mail server, we suggest you use service from another provider. If it is your own mail server, please apply for an SSL certificate for it as soon as possible.

Yes, this is a problem indeed. The traditional method of analyzing the content of emails to determine whether they are SPAM, malicious URL and malicious attachments is no longer applicable. It must be handled by other means.

MeSince adopts an advanced mode of SPAM and malicious mail scanning by cloud computing. For URL links and attachments to emails, they are identified using Security Technology's sophisticated cloud scanning technology. If malicious emails (containing malicious attachments and malicious link) are identified, then the user is prompted to delete this message and it will be automatically archived in the "MalMail" directory.

For SPAM, MeSince uses cloud recognition technology to intercept SPAM, that is, to use the wisdom and strength of the majority of users. As long as the user reports an email as SPAM, the APP uploads the email address and IP address to the cloud server. The number of user reports to determine whether other users receive emails sent from this email address are automatically moved to the trash or directly deleted.

At the same time, in order to prevent misjudgment, user can add any trusted email address to the address book or whitelist so that even if other users have reported it as SPAM, the user will still normally process the email from the trust list. We firmly believe that your active participation will completely help us to eliminate SPAM.

Very good choice! Yes, because each email is encrypted, you can safely send all kinds of confidential information to your own mailbox. Only you can open it, and even the mailbox provider cannot read it. It ensures that all confidential information stored in your own mailbox is more secure than in traditional cloud.

It is recommended that you create a separate folder in your mailbox for your confidential information email. At the same time, special attention should be paid that the certificate protection password must be set for your encrypting certificate, then even if somebody has hacked your mailbox and get your encrypted email, your confidential info will still be safe since nobody know your encryption certificate protection password.

If you have any questions, please visit Forum, you may find your answer very quickly.