#### SMTP

By default this system uses php mail() function for sending outgoing emails from system. Php mail() function will work if you have sendmail installed at your server – in your server php.ini file if you have sendmail enabled then the php emails are script based emails so there is possibility that your outgoing emails may be marked as spam or land in customers junk folder.

SMTP section will allow you to use your own outgoing email server.
Once you have added your outgoing email server, Go to Settings >> Domains >> Default outgoing email -- change it to your newly added outgoing email instead of php mail. (This setting is used for sending emails that company based example forgot password, client registration email)
Queue outgoing emails for delivery
When you add your own outgoing email server in this system there is chance it might take some time to connect to your email server from server where you have this script installed depending on latency and server locations. If you experience delay in sending emails when you hit submit button on ticket reply or new ticket creation then you can turn on "Queue outgoing emails". With this setting on your outgoing emails will be queued for delivery and sent in background. (This will remove the interface delay while hitting submit button for new ticket or reply ticket).
You will have to set cron job or a scheduler to run in background to process the outgoing email queue. Contact our support team for help related to setting cron job.