The online-store email stack
Marketing flows that read your store, with receipts kept safely apart.
For an online store, revenue comes from flows: the welcome series, the abandoned-cart nudge, the win-back campaign. That means your marketing platform needs to read your store data — products, orders, browsing — so the right message goes to the right person at the right moment. Klaviyo does this natively for most storefronts, which is why it is our pick; Omnisend is a capable alternative if you want SMS tightly integrated.
The critical decision is separation. Your order confirmations and shipping notices must arrive in seconds, every time, no matter what your marketing is doing. Put them on a dedicated transactional service — Postmark for its speed and reliability, or Amazon SES if you want the lowest per-message cost and can handle more setup. A campaign problem should never delay a receipt.
Keep the list clean with ZeroBounce so hard bounces do not erode your reputation, and watch that reputation in Google Postmaster Tools. The mailbox itself — where replies and support land — sits on Google Workspace, kept separate from all bulk sending.
The shape that works: one place for marketing that knows your store, a separate place for receipts that never goes down, and clean data feeding both.