Twilio SMS and MMS messages, including message bodies and records, are kept in Twilio's cloud storage until a customer requests them be removed. Customers can request messages to be deleted at any time via an HTTP DELETE request.
Once an HTTP DELETE request is received, the corresponding message is removed from the customer-facing repository that holds messages. Deleted messages cannot be recovered. Message bodies may persist for up to 30 days after an HTTP DELETE request in our database backups.
Message data retention period for Twilio Console and Messages API
Starting October 14, the Message Logs in the Twilio Console and the Messages API Resource will display message records for up to 13 months after the message is created. With the exception of Twilio Programmable Chat and Conversations, this new data access policy will apply to all Messaging Channels - SMS, MMS, WhatsApp, etc.
Message records older than 13 months will not be deleted from Twilio – all the data other than media attachments will remain accessible indefinitely through the Bulk Export API or from the Twilio Console under Programmable Messaging / Settings / Archives.
Message media retention period
Message media objects (e.g. MMS attachments) older than 13 months are permanently deleted.
Message media objects are images, audio files, or other attachments that you have sent or received using MMS or WhatsApp Media messages.
For more information see Changes to availability of Message Records and Media attachments (October 2020)