Guides and compliance updates
Plain-English guides on TRAI SMS rules, DLT changes, OTP security and email deliverability, written by the AvanceZone team and dated so you know they are current.
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TRAI SMS Rules
In 2026 every business SMS in India must come from a DLT-registered entity, header and template, through a declared PE to…
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OTP Security
To secure SMS OTP, keep codes short-lived and single-use, limit OTP requests per number, IP address and device, and put a captcha…
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Email Deliverability
To reach Gmail, Yahoo and Outlook inboxes, send from your own domain with SPF and DKIM passing and a DMARC record of at least…
Read more →Why these guides are dated
Messaging rules in India change several times a year. TRAI has added header suffixes, URL whitelisting and sender chain checks since 2024, and email inbox providers tightened their own rules in the same period. Each guide shows the date it was last checked, so you know whether it reflects the rules in force today.
Start with TRAI SMS rules if your messages are being rejected or you are setting up DLT for the first time. Read OTP security if you send login codes from a website or app, and email deliverability if your emails land in spam. For registration steps, see the DLT registration guide.
Every guide is written by the SMS Gateway Providers team at AvanceZone Technology, Coimbatore, and checked against the regulator's or the provider's own published rules.
Last updated 1 November 2026 by the SMS Gateway Providers team at AvanceZone Technology, Coimbatore.
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