ServiceDesk Plus Cloud allows you to configure the incoming e-mail settings and the outgoing e-mail settings such that it fetches the emails that are sent to the IT help desk team and sends notifications/feedback to the technicians, requesters, and vendors.
>> Mail Settings >> Mail Server Settings link. The Mail Server Settings page displayed will be as shown in the figure:

All the fields marked * are mandatory fields.
Enter the server name, user name, password, e-mail address, email type, port, and the time interval in which the mail needs to be fetched periodically. The time period is in minutes. The e-mail type is a combo box from which you need to select the value.
If you want to receive emails from other unknown users and select the checkbox next to Accept E-Mails from unknown users
Enter the outgoing mail server name / IP address and reply-to e-mail address. These are the mandatory fields.
Enter the name of the sender in the Sender's Name field.
Choose the e-mail type, which is usually SMTP and SMTPS. By default, the port associated with SMTP is 25 and the port associated with SMTPS is 465.
If required, you can choose SMTP with Transport Layer Security (TLS) from the drop-down.
If your SMTP server for outgoing mails requires authentication, then select the checkbox Requires Authentication.
Enter the User Name and Password in the respective fields. These are the mandatory fields.
Email Request Settings
To prevent request creation through emails, select the Disable new request creation through email checkbox. Optionally, you can allow request creation through specific domains and email addresses. Enter the excepted list of domains and email addresses in the field below the checkbox, as demonstrated in the following screenshot:

In the above sample, emails from the specified domain 'zylkersupport.com' and the email addresses will be fetched by the application and created as requests. Other emails will be rejected.
Note that this restriction does not apply to emails that append as conversations to requests/changes.
When an email is rejected, an automated notification will be sent to the requester. You can configure and customize this notification under Setup >> Automation >> Notification Rules >> Request >> Notify Requester when their new request created by email is rejected.
After configuring the settings, click Save.
The configurations will be saved and ServiceDesk Plus Cloud will try to establish a connection with the mail server. On a successful connection, the mail fetching status is enabled. To start the mail fetching, click Start Fetching button. Now, the Save button is disabled. If you wish to make any changes to the incoming mail server settings, then you need to stop mail fetching and only then make the changes and save them.