The SMS relay field is found inside the VoIP line configuration settings as shown below in red:  It is used to send an email alert to you if you receive a reply to an SMS message that you sent via the system.  

Please DO NOT enter a phone number or mobile number here.

Please only enter an email address in this field as this will send an SMS message via email to you containing the message details as shown in the example below:

If you wish for the email SMS alert to be sent into your CRM account just enter your CRM account email drop box address into this field as shown below:

If you are unsure what your CRM email drop box address is it will be the following: 

When someone replies to an SMS message you have sent via the CRM (please click here to see how to send an SMS message), then their reply will automatically be sent into your CRM account and shown on the Dashboard as in the screenshot below:

By clicking on the Dashboard entry it will take you into the History where you can view the full details of the SMS message you have received in via your CRM mailbox.

If you have any questions about any of the above please contact our Support Helpdesk.