"Infrastructure region" sounds like a detail you shouldn't have to think about. For a transactional email platform sending to Indian recipients, it actually matters for two separate reasons: physical proximity, and legal jurisdiction. They're easy to conflate, so it's worth separating them.
Latency: proximity, not magic
Network latency roughly tracks physical distance and the number of hops in between. An API call from a server in Mumbai to AWS SES in the same region (ap-south-1) travels a much shorter path than the same call routed to a US or Singapore data center and back. The same logic applies on the delivery side: SES handing a message to an Indian recipient's mail server from inside India involves fewer network hops than handing it off from another continent.
We won't cite a specific millisecond figure here without a proper field-measured benchmark to back it up -- if you're evaluating this for a latency-sensitive use case (an OTP that needs to land before a user gives up on a login screen, for example), measure your own actual round-trip time against whatever provider you're considering, rather than trusting anyone's marketing number, including ours. What you can reason about without a benchmark is the shape of the problem: every hop a packet makes adds propagation delay, and a request that leaves India, gets processed, and comes back has strictly more hops than one that never leaves.
Compliance: what the DPDP Act actually requires
It's a common assumption that Indian data protection law requires all personal data to be stored inside India. That's not quite what the Digital Personal Data Protection Act, 2023 (DPDP Act) says: it doesn't impose a blanket data-localization mandate for all personal data. Instead, it gives the central government the power to restrict transfers of personal data to specific countries it notifies -- a blacklist approach, not a default requirement to keep everything in India.
Sector-specific rules elsewhere are a separate, narrower story. The Reserve Bank of India's 2018 directive on storage of payment system data requires payment system providers to store payment transaction data only in India, with processing allowed overseas as long as the data is deleted from foreign systems within the prescribed window. That predates the DPDP Act, applies specifically to payment data, and has nothing to do with email -- it's worth knowing about only so you don't confuse it with a general email-data-residency rule that doesn't exist.
So choosing India-based sending infrastructure isn't about satisfying a specific DPDP Act clause that doesn't exist in that blanket form. What it does do is remove an entire category of cross-border-transfer questions before they come up, and it lines up with the data-residency expectations many Indian enterprise customers, auditors, and procurement teams already have baked into their own vendor checklists -- independent of whether the law strictly requires it. A procurement team that asks "where does our customer data live" gets a one-sentence answer instead of a legal memo.
This is general information, not legal advice. Talk to counsel about your specific compliance obligations under the DPDP Act and any sector-specific rules that apply to your business.
What MailKaka actually does here
MailKaka sends and receives email through Amazon SES in the Mumbai region (ap-south-1), and stores attachments in S3 in the same region. That claim is specifically about the email-sending infrastructure -- it's the part that matters for the latency and data-residency reasoning above.
For how that compares to running SES directly yourself -- same underlying infrastructure, different setup and tooling burden -- see MailKaka vs Amazon SES.