hermes-skills/skills/devops/infrastructure-automation/references/smtp-gateway-notes.md

SMTP Delivery Failures: email-to-SMS Gateways

AT&T Gateway Shutdown

AT&T shut down its email-to-SMS and SMS-to-email gateways (@txt.att.net, @sms.att.net) as of 2026. Messages to number@txt.att.net bounce with:

554 5.7.1 <recipient>: Recipient address rejected: MXroute has blocked this recipient

Tested and confirmed bouncing from MXroute (mail.germainebrown.com) on July 4, 2026.

Affected Cron Jobs

• Daily brotherly-torment SMS to Tony (7853752998@txt.att.net) — silent failure since July 4

Recommendations

• Use Twilio (~$0.0079/SMS, ~$1/mo per number) for reliable programmatic SMS
• Google Voice (free) if you already have a Google Voice number
• TextBolt ($3-5/mo) or TXTImpact ($10-15/mo) as alternatives
• If using a carrier gateway for personal cron jobs, verify quarterly by sending a test message and checking for a bounce-back in the inbox