Cannot configure SMTP (SSL/TLS) with my provider

docker
nc15

#1

Nextcloud version 15.0.0.10 / Offical “_latest” Docker Image
Operating system and version: Linux / Synology NAS / Docker

The issue:
Trying to configure the SMTP server of my internet provider with Nextcloud I always get below error message

The output of your Nextcloud log in Admin > Logging:

Error	ocs_api	OCP\AppFramework\OCS\OCSException: Unable to send the invitation mail	
2018-12-30T09:50:38+0100
Error	ocs_api	Swift_TransportException: Connection could not be established with host mail.mnet-online.de [ #0] Log data: ++ Starting Swift_SmtpTransport !! Connection could not be established with host mail.mnet-online.de [ #0] (code: 0)	
2018-12-30T09:50:38+0100

Thats what I try to configure (translated from German:
Send mode: SMTP
Encryption: SSL/TSL
From address: (Address does exist)
Authentication method: plain text (I tried also all ather options)
Server address: mail.mnet-online.de:587
Credentials (are correct)

The server does not allow unsecure connections, so I cannot try without SSL/TLS. This server configuration works in all other places I use (Thunderbird, Outlook, Synology DSM, iOS Mail).

My config.php:

<?php
$CONFIG = array (
  'htaccess.RewriteBase' => '/',
  'memcache.local' => '\\OC\\Memcache\\APCu',
  'apps_paths' =>
  array (
    0 =>
    array (
      'path' => '/var/www/html/apps',
      'url' => '/apps',
      'writable' => false,
    ),
    1 =>
    array (
      'path' => '/var/www/html/custom_apps',
      'url' => '/custom_apps',
      'writable' => true,
    ),
  ),
  'instanceid' => '(hidden)',
  'passwordsalt' => '(hidden)',
  'secret' => '(hidden)',
  'trusted_domains' =>
  array (
    0 => '(hidden)',
  ),
  'datadirectory' => '/var/www/html/data',
  'dbtype' => 'mysql',
  'version' => '15.0.0.10',
  'overwrite.cli.url' => '(hidden)',
  'dbname' => 'nextcloud',
  'dbhost' => '192.168.178.97:3306',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'nextcloud',
  'dbpassword' => '(hidden)',
  'installed' => true,
  'mail_smtpmode' => 'smtp',
  'mail_sendmailmode' => 'smtp',
  'mail_from_address' => 'cloud',
  'mail_domain' => '(hidden)',
  'mail_smtpauth' => 1,
  'mail_smtphost' => 'mail.mnet-online.de',
  'mail_smtpport' => '587',
  'mail_smtpsecure' => 'ssl',
  'mail_smtpauthtype' => 'PLAIN',
  'mail_smtpname' => 'm1000066655',
  'mail_smtppassword' => '(hidden)',
  'maintenance' => false,
  'mail_smtpdebug' => true,
);

Many thanks to whoever bothers to look at this…

Gerhard


#2

Finally I was able to solve the problem by replacing port 587 with 465.

I do not understand, though, why all other clients work with port 587 which also is the port my provider officially has documented. But anyway it works no.