ssl - 即使存在有效证书，私有(private)邮件服务器也会给出证书错误

Question

我使用 iRedMail 和 Nginx 创建了一个私有(private)邮件服务器。我已经在以下位置将 SSL 证书和 key 安装到 Nginx 和 iRedMail 中。服务器运行良好，一切都通过网络邮件工作。浏览器同意 SSL 证书有效并且 HTTPS 有效。

问题是当我将邮件帐户添加到我的电子邮件客户端时，我收到无效证书错误，并且在使用 CalDav 时出现同样的问题。它仍然有效，但这让我觉得我在某处遗漏了一些证书安装。有什么建议么？谢谢!

/etc/ssl/certs/iRedMail.crt
/etc/ssl/private/iRedMail.key

这是 openssl s_client -showcerts -connect mail.bragsdale.dev:993 的输出

CONNECTED(00000003)
depth=0 CN = bragsdale.dev
verify error:num=20:unable to get local issuer certificate
verify return:1
depth=0 CN = bragsdale.dev
verify error:num=21:unable to verify the first certificate
verify return:1
---
Certificate chain
 0 s:/CN=bragsdale.dev
   i:/C=US/O=Let's Encrypt/CN=Let's Encrypt Authority X3
-----BEGIN CERTIFICATE-----
...CERTIFICATE HERE...
-----END CERTIFICATE-----
---
Server certificate
subject=/CN=bragsdale.dev
issuer=/C=US/O=Let's Encrypt/CN=Let's Encrypt Authority X3
---
No client certificate CA names sent
Peer signing digest: SHA512
Server Temp Key: ECDH, P-256, 256 bits
---
SSL handshake has read 2064 bytes and written 431 bytes
---
New, TLSv1/SSLv3, Cipher is ECDHE-RSA-AES256-GCM-SHA384
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
    Protocol  : TLSv1.2
    Cipher    : ECDHE-RSA-AES256-GCM-SHA384
    Session-ID: 3DD2E8B607CF5B4ACECDB995078FDAE80C210097372B80CD1409E90A0A523E0A
    Session-ID-ctx: 
    Master-Key: F1953ABEAC1024279DA6D0E17D26E3305E7C2A9589976FDFD2DBF22E4B6280415BC271E5228045B7D0C5E8A0B3921B11
    Key-Arg   : None
    PSK identity: None
    PSK identity hint: None
    SRP username: None
    TLS session ticket lifetime hint: 300 (seconds)
    TLS session ticket:
    ....DATA HERE...

    Start Time: 1551664367
    Timeout   : 300 (sec)
    Verify return code: 21 (unable to verify the first certificate)
---
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE AUTH=PLAIN AUTH=LOGIN] Dovecot ready

Answer 1

修复它。问题是我没有使用我的中介证书。 See this answer for details.

请注意，当我将证书放在一起时，它的格式是错误的，END CERTIFICATE/BEGIN CERTIFICATE 在一行上。使用文本编辑器轻松修复。