Edit History

• Servidor software: exim.
• Puerto: 465
• Seguridad TLS 
• user y contraseña
• Servidor: el hostname con certificado

Prueba de concepto de operatividad TLS en el puerto indicado

root@tiendas:/home/admin/domains# h=tiendas.midominio.tld
root@tiendas:/home/admin/domains# p=465
root@tiendas:/home/admin/domains# openssl s_client -connect $h:$p -tls1_2
CONNECTED(00000003)
depth=2 C = US, ST = New Jersey, L = Jersey City, O = The USERTRUST Network, CN = USERTrust RSA Certification Authority
verify return:1
depth=1 C = GB, ST = Greater Manchester, L = Salford, O = Sectigo Limited, CN = Sectigo RSA Domain Validation Secure Server CA
verify return:1
depth=0 CN = *.midominio.tld
verify return:1
---
Certificate chain
 0 s:CN = *.midominio.tld
   i:C = GB, ST = Greater Manchester, L = Salford, O = Sectigo Limited, CN = Sectigo RSA Domain Validation Secure Server CA
 1 s:C = GB, ST = Greater Manchester, L = Salford, O = Sectigo Limited, CN = Sectigo RSA Domain Validation Secure Server CA
   i:C = US, ST = New Jersey, L = Jersey City, O = The USERTRUST Network, CN = USERTrust RSA Certification Authority
 2 s:C = US, ST = New Jersey, L = Jersey City, O = The USERTRUST Network, CN = USERTrust RSA Certification Authority
   i:C = GB, ST = Greater Manchester, L = Salford, O = Comodo CA Limited, CN = AAA Certificate Services
 3 s:C = GB, ST = Greater Manchester, L = Salford, O = Comodo CA Limited, CN = AAA Certificate Services
   i:C = GB, ST = Greater Manchester, L = Salford, O = Comodo CA Limited, CN = AAA Certificate Services
---
Server certificate
-----BEGIN CERTIFICATE-----
MIIGMzCCBRugAwIBAgIQBD0YRSjZNjtUR8JjJlLGNjANBgkqhkiG9w0BAQsFADCB
jzELMAkGA1UEBhMCR0IxGzAZBgNVBAgTEkdyZWF0ZXIgTWFuY2hlc3RlcjEQMA4G
...
oWupn06TJM9t2smn35+gAq176aHqi/PibQoI+jDasc0cD3BDgGKQqQtxNL2iwUAQ
bzfStxJHbJpMJyGDu4FOgaFER/GdUBO5DoyoxwuEDrqTG5P2jHTQRA4eM8n2iuVP
WWi1pzQLx9WdA+70kghYXyrX2MU37u7jQwq0KNefOd09QLWnJKyJ9/GWv1a9S/sK
wOnA7HY8RuriWpXp+8MGVklJF/iZ2f0VBpcZk9AdepwZGC4QuOkru8OeQQSWMaYh
eQuBYFtPqg==
-----END CERTIFICATE-----
subject=CN = *.midominio.tld

issuer=C = GB, ST = Greater Manchester, L = Salford, O = Sectigo Limited, CN = Sectigo RSA Domain Validation Secure Server CA

---
No client certificate CA names sent
Peer signing digest: SHA256
Peer signature type: RSA-PSS
Server Temp Key: X25519, 253 bits
---
SSL handshake has read 6132 bytes and written 310 bytes
Verification: OK
---
New, TLSv1.2, Cipher is ECDHE-RSA-AES128-GCM-SHA256
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-AES128-GCM-SHA256
    Session-ID: F1258D3539056F4F6DA8D3A85DCB2CFFECD18E29961A313D66A02EC01A466576
    Session-ID-ctx: 
    Master-Key: 39FBC4AF1159F0718D486F7649B2BE1A5D9265AAADD454FB52929773AE47265BB34420DA2C32D27562A6BFCD27BB9B8E
    PSK identity: None
    PSK identity hint: None
    SRP username: None
    Start Time: 1624604185
    Timeout   : 7200 (sec)
    Verify return code: 0 (ok)
    Extended master secret: yes
---
220 tiendas.midominio.tld ESMTP Exim 4.94.2 Fri, 25 Jun 2021 06:56:25 +0000

Log servidor

2021-06-25 07:00:12 TLS error on connection from tiendas.midominio.tld [178.32.236.129] SSL_accept: TCP connection closed by per

Mensaje en el dashboard

Error. Por favor comprueba tu configuracion

Connection to tpc://tiendas.granadacf.es:465 Timeout

Sin SSL puerto 25

Error: Por favor, comprueba tu configuración

Expected response code 354 but got code "503", with message "503-All RCPT commands were rejected with this error: 503-No such recipient here 503 Valid RCPT command must precede DATA "

Alguna idea ?