ESPs

Email marketing software, by ESP category

ESPs are not one product. Newsletter tools, commerce engines, B2B hubs, and transactional APIs solve different jobs.

An ESP is the pipe and the database

Email marketing software usually means an email service provider: it stores subscribers, builds campaigns, tracks clicks, and talks SMTP to Gmail and Microsoft. It is not Photoshop. It is not your CRM, unless you bought a suite that swallowed both. If you pick software by logo familiarity, you will use a newsletter tool as a commerce engine and then blame 'email.'

Authentication (SPF, DKIM, DMARC) still sits in DNS. The ESP gives you records to paste. That setup is email-aisle work. The software will not magically warm a brand-new domain you blast on day one.

ESP

Audience · Template · Send

One product. Auth, unsubscribes, bounces live here.

Software here means the sending product: audience, template, send.

Newsletter and SMB tools

Mailchimp, Constant Contact, Brevo, Kit: audiences, campaigns, simple automations, forms. Fine for publishers, local services, and simple catalogs. Weak when you need SKU-level browse events or a sales-team CRM as the source of truth. Their editors are the product. That is a compliment if you send campaigns. It is a limit if engineers need an API-first transactional stream.

Commerce ESPs

Klaviyo is the example most store teams name. The center is the profile plus events from Shopify or similar: placed order, viewed product, started checkout. Flows fire on those events. If you do not have a store feed, you are paying for a machine you are not feeding. Other commerce-leaning tools exist. The category test is: can a 'viewed these three SKUs, did not buy' segment be built without a spreadsheet?

B2B hubs and transactional specialists

HubSpot, Adobe Marketo, Salesforce Account Engagement: email is one object next to forms, landing pages, and a CRM. You buy them when sales and marketing share a contact database and a lead status. You overbuy them when you needed a newsletter. ActiveCampaign sits between SMB automation and that hub world.

Transactional software (SendGrid, Postmark, Amazon SES, Mailgun) is for receipts and product mail. High deliverability expectations, API sending, less of a campaign calendar. Using SendGrid as your only newsletter tool is possible and usually miserable. Using Mailchimp as your only password-reset pipe is how resets land in promotions.

Common questions

Is Gmail email marketing software?

No. Gmail is a mailbox. BCC'ing 40 customers from your inbox is not an ESP. You get no list hygiene, no unsub header that scales, and a fast path to looking like a spammer. Use an ESP once you leave personal correspondence.

Can one ESP cover campaigns and transactional?

Some vendors sell both. Many teams still split them so a promo cannot tank receipt delivery. If you combine them, use separate subdomains (mail. vs send.) so reputation is isolated. That is email-aisle architecture.

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