To see your Webmail Auto-Reply settings, log into webmail.srt.com and click on Preferences and select the Mail tab. Your settings for Auto-Reply are in the Receiving Messages section. See example below.
To add an auto-reply in the new Webmail when it becomes available on May 13, log into webmail.srt.com, open your Setting by clicking the Settings icon [Gear], then click Mail Preferences and click Auto-Reply Message. Locate the Auto-Reply Message section, Click Enable Auto-Reply, add your reply text and click Save. See example below.