Configure email transport for Kimai

Kimai uses the Symfony Mailer component for sending emails. Please read their documentation to find out more about possible connection details.

Activating email

You have to adapt two settings in your .env configuration file:

  • MAILER_URL - the connection details for sending emails
  • MAILER_FROM - an application wide “from” address for all emails


The following providers are supported out-of-the-box by Kimai:

  • Deactivated: null://null
  • SMTP: smtp://localhost:25

The following specialized transports (usually helper to simplify the connection string) can be installed manually:

Service Install with SMTP config example
Amazon SES composer require symfony/amazon-mailer ses+smtp://USERNAME:PASSWORD@default
Gmail composer require symfony/google-mailer gmail+smtp://USERNAME:PASSWORD@default
MailChimp composer require symfony/mailchimp-mailer mandrill+smtp://USERNAME:PASSWORD@default
Mailgun composer require symfony/mailgun-mailer mailgun+smtp://USERNAME:PASSWORD@default
Mailjet composer require symfony/mailjet-mailer mailjet+smtp://ACCESS_KEY:SECRET_KEY@default
Postmark composer require symfony/postmark-mailer postmark+smtp://ID@default
SendGrid composer require symfony/sendgrid-mailer sendgrid+smtp://KEY@default
Sendinblue composer require symfony/sendinblue-mailer sendinblue+smtp://USERNAME:PASSWORD@default
OhMySMTP composer require symfony/oh-my-smtp-mailer ohmysmtp+smtp://API_TOKEN@default

Be aware that you can achieve the same in most cases (without installing composer packages) by rewriting the MAILER_URL, e.g.:

  • Gmail: smtps://{username}:{password}
  • Sendinblue: smtps://{username}:{password}

Read more at Symfony docs


You can test your email configuration by registering a new account or using the password reset function.

During your initial tests, you might try to use the password reset function over and over again. That will not work, as Kimai stores a timestamp when the last password reset was requested and does not allow another request in a certain timespan.

To work around that waiting time, you can reset the timer by issuing the following command (replace the username with yours):

bin/console doctrine:query:dql "UPDATE App\Entity\User u SET u.passwordRequestedAt = null WHERE u.username = 'anna_admin'"

MAILER_URL with special character

If your SMTP credentials contain special character like @ or other ones which are not URL-safe, then they need to be urlencoded. This can be done with one command, assuming your password is mG0/d1@3aT.Z)s then execute:

php -r "echo urlencode('mG0/d1@3aT.Z)s');"

Your MAILER_URL might look like this:


SMTP does not accept emails

If you have the following error in your logfile:

app.ERROR: Exception occurred while flushing email queue: Expected response code 354 but got code "503", with message "503-All RCPT commands were rejected with this error: 503-R1: HELO should be a FQDN or address literal (See RFC 2821 503 Valid RCPT command must precede DATA " [] []

you might suffer from a wrong configuration (read the documentation linked above) and try a fully featured SMTP URL with a dedicated user account for authentication:


Password should not contain URL characters like ‘&@:’, which can cause problems parsing the SMTP URL (see above).