If we are unable to deliver a message for an amount of time that exceeds its time-to-live, we will stop retrying and drop the message. By default, messages that use an authentication template have a default TTL of 10 minutes, and messages that use a utility or marketing template have a default TTL of 30 days. Set its value between 30 and 900 seconds (i.e., 30 seconds to 15 minutes) for authentication templates, or 30 and 43200 seconds (i.e., 30 seconds to 12 hours) for utility templates, or 43200 and 2592000 seconds (i.e., 12 hours to 30 days) for marketing templates. Alternatively, you can set this value to -1, which will set a custom TTL of 30 days for either type of template. We encourage you to set a time-to-live for all of your authentication templates, preferably equal to or less than your code expiration time, to ensure your customers only get a message when a code is still usable. Authentication templates created before October 23, 2024, have a default TTL of 30 days.