> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://help.flexbox.cloud/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# What are the requirements for digitally signing and encrypting an email?

First import and configure your S/MIME Certificate in your system or mail client.

To send a digitally signed email, the recipient does not need to have an S/MIME Certificate. Your digital signature will automatically be validated.

Email encryption is only possible if both sender and recipient have a valid S/MIME certificate and the public keys have been exchanged in advance. 
To exchange the public keys, simply exchange a digitally signed email with the recipient.


If you don't have an S/MIME Certificate or need to renew your existing one, check out our offerings: [https://flexbox.cloud/en/secure-email-smime-certificate/](https://flexbox.cloud/en/secure-email-smime-certificate/)