Knowledge Base

How to Configure an email S/MIME certificate with Android

Updated on March 10, 2026

How to Configure an Email S/MIME Certificate on an Android Device?

Overview

This guide provides the step-by-step process for exporting, transferring, installing, and verifying an S/MIME email certificate on an Android device. Following these instructions ensures secure email communication using digital signing and encryption.

Prerequisites

Before you begin, ensure you have the following:

The S/MIME certificate already collected on your computer

The certificate exported in PFX/P12 format, including the private key

A strong password set for the exported certificate file

A method to transfer the certificate to your Android device (e.g., email, USB drive, cloud storage)

Procedure

Step 1: Export the Certificate from Your Computer

Export your S/MIME certificate into a PFX/P12 file.
Ensure that:

The private key is included

All certificates in the chain are included (if possible)

You set a strong password to protect the file

Step 2: Transfer the Certificate to Your Android Device

Send or move the exported PFX/P12 file to your Android phone using any preferred secure method, such as:

Emailing it to yourself

Copying it via USB

Uploading and downloading from cloud storage

Step 3: Open and Install the Certificate

Tap the PFX/P12 file on your Android device to open it.

Upon clicking the Download button, an “Extract Certificate” pop-up window will appear. When prompted, enter the password used during certificate export.

A pop-up titled Extract Certificate will appear. Tap OK.

Step 4: Choose Certificate Type

When prompted to select a certificate type, choose:
VPN & app user certificate
Then tap OK to proceed.

Step 5: Name the Certificate

A default alphanumeric name will be assigned.
You may rename it to something more recognizable, then tap OK.

A message will appear saying that your S/MIME certificate has been installed on your Android device

Step 6: Confirm Installation

Once you confirm the name for your certificate and click the OK button, you will see the message: User certificate installed.

You can now proceed to check the S/MIME certificate you have downloaded on your phone.

Step 7: Check the Security settings of your Android phone

Go to Settings and click Security

Next, click Encryption & Credentials

Click User credentials

Click on the S/MIME certificate you have installed to check its details.

Since it has been downloaded as a PFX file, you will see that your certificate contains your user key/private key, your actual certificate, and the CA certificate which assures your device that your certificate can be trusted.