If you are going on vacation and will not be able to check your mail for a while, you may want to leave a vacation notice that will be automatically sent to your correspondents once they send e-mail to your address. This is done with automatic reply facility, also referred to as autoresponder. Aside from vacation notices, organizations can use automatic replies to notify customers that their orders or technical support requests were received and will soon be processed. Automatic replies can include prewritten messages in plain text or HTML format, and they can contain attached files as well.

Log in to the Plesk control Panel using the link https://yourdomain.com:8443

Click the Create Autoresponder icon from Mail  menu.

 Click the e-mail address, for which you wish to set up an automatic reply and click  "Next".

Configure the automatic reply:

Type a name for this automatic reply into the Autoresponder name box. 

For example, Test Autoresponder.

If you want your incoming mail to be forwarded to another e-mail address while you are away, specify an e-mail address in the Upon automatic response, forward the original message to the specified e-mail box.

If you want this automatic reply to be sent in reply to any incoming e-mail message, in the Conditions group, leave the always respond option selected. If you wish to automatically reply only to e-mail messages that contain specific words in the message text or subject line, select the appropriate option, and type the word combination in the input box.

By default, the subject line of incoming e-mail will be inserted into the automated reply. To use a custom subject, type it into the Reply subject input box.

As your correspondents may not figure out that the message they received from you was an automatic response, they may want to respond to your auto-reply. So, you should specify your e-mail address as the Return address, otherwise, their messages will be directed at the autoresponder's address.

Specify the automatic reply message format (plain text or HTML) and character encoding (UTF-8 is recommended). If you use HTML tags in your auto-reply message, you should select the HTML option.
Type your message in the Reply with text field.

Attach your files, if needed. To do this, click the Add New Attachment button, select the check box corresponding to the file that you previously uploaded to the attachment storage, and click OK. To remove an attached file from the automatic reply, select the corresponding checkbox, and click Remove Selected.

To limit the number of automated responses per day to the same e-mail address, enter the desired number in the respective input box under Limits.

The default setting is to respond no more than ten times in one day to the same e-mail address.

To reduce mail server load, you may want to limit the number of unique addresses that the autoresponder will remember. To do this, enter the desired number into the Store up to box.

Click OK.

 Now you can see that your "Autoresponder" is created, Click on "Switch On" icon to enable the service.

Now you can see the autoresponder service is activated .

Don't forget to Logout after you have finished.