Configure SMTP for outbound emails

Horde can be configured to use either a local mail agent or a third-party SMTP server for outgoing email.

For example, to configure Horde with a Gmail account using IMAP for incoming email and SMTP for outgoing email, update the /opt/bitnami/apps/horde/htdocs/imp/config/backends.php file as shown below:

$servers['imap'] = array(
    'disabled' => false,
    'name' => 'Gmail IMAP server',
    'hostspec' => '',
    'hordeauth' => false,
    'protocol' => 'imap',
    'port' => 993,
    'secure' => 'ssl',
    'maildomain' => '',
    'smtp' => array(
        'auth' => true,
        'localhost' => 'localhost',
        'host' => '',
        'password' => 'PASSWORD',
        'port' => 587,
        'secure' => 'tls',
        'username' => 'USERNAME'
    'cache' => false,

Replace USERNAME and PASSWORD with your Gmail account username and password respectively.

For more information, refer to the Horde documentation.

To configure the application to use other third-party SMTP services for outgoing email, such as SendGrid, refer to the FAQ.

NOTE: If you are using Gmail as the outbound email server, your application’s attempts to send outgoing emails may be blocked by Gmail if it considers the authentication attempts to be suspicious. When this happens, you will receive a Gmail security alert at the corresponding Gmail address. To proceed, you will need to manually confirm the validity of the authentication attempt before Gmail will permit the application to send outbound emails. For more information on this and other Gmail issues related to outbound email from your application, refer to our Gmail SMTP troubleshooting page.

Last modification November 17, 2020