SMS Reply Automation
With Auto Replies you can add simple automation to SMS-enabled phone numbers and send general or keyword-related replies to SMS messages received on these numbers.
Automatic replies can include images and can be scheduled for specific dates or times. If you have multiple replies for a number, you can select priorities to determine the order they are delivered.
Existing and New Auto Replies
The Auto Replies screen is accessed at Admin Center Menu>SMS Features>Auto Replies. Select any auto-reply to edit it or check one or more auto-replies and select 
to delete them.
Select 
on the top-right to download a CSV list of existing auto replies. Select 
to search for a specific auto replies.
Selecting ADD AUTO-REPLY creates a new auto-reply and directs you to its settings page (see next).
Auto-Replies Settings
Select any auto-reply or create a new one to show and configure its settings.
Name/Description: Self-explanatory. The description is optional.
Phone Number: Select a phone number to apply the auto-reply to.
Reply Once in: Select the frequency of replies — Once Per Phone Number or every 1-12 hours, 1-6 days, 1-3 weeks, or every month.
Default Message/Attachment: Enter the text of the auto-reply message.
(optional) Drop or select a file in the Attachment field to be included with the auto-reply message.
Priority: Select an auto-reply priority from 1 (highest) - 10 (lowest).
If you have auto-replies for the same number with the same schedule the highest priority will be delivered first.
Keywords: Enter any keywords that trigger the auto-reply (if the keywords you select are not present in a message the auto-reply will not be sent).
You cannot use the 'start', 'stop', and 'help' keywords as they are reserved for the system.
Schedule: From the Schedule Type drop-down list select Days of Week, Days of Month, or Date Range) and then check the relevant days or select a date range when the auto-reply will be in effect.
If you want the auto-reply to be in effect at all times select Days of Week and check all the days.
Start/End Hour: CTIA Messages Best Practices and The Campaign Registry (TCR) require that you avoid sending messages during quiet hours — generally 9 pm to 8 am. Here you can limit the message delivery to a specific time range to respect quiet hours.
However, since you are not sending a message but replying to one it can be assumed the sender expects an instant reply even not during quiet hours. To accommodate this and reply 24 hours a day leave the Start/End hour at 12 AM.
Enable/Disable: A toggle that allows you to temporarily disable an auto-reply instead of deleting it.