Windows 10 reached EOS (end of support) on October 14, 2025. For more information, see this article.

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

This thread was archived. Please ask a new question if you need help.

How to specify encryption cipher for S/MIME mails

  • No replies
  • 1 has this problem
  • 3 views
garliccheese
garliccheese
more options

I use S/MIME to encrypt mails. Thunderbird uses AES128 for the encryption, but I have some contacts who are technically limited to 3DES.

I'm aware of the cryptographic weaknesses of 3DES, but this is the only method I can use to encrypt mails for these contacts.

How can I specify the encryption cipher for S/MIME emails I send in Thunderbird?

I use S/MIME to encrypt mails. Thunderbird uses AES128 for the encryption, but I have some contacts who are technically limited to 3DES. I'm aware of the cryptographic weaknesses of 3DES, but this is the only method I can use to encrypt mails for these contacts. How can I specify the encryption cipher for S/MIME emails I send in Thunderbird?