day3 sends marketing and transactional email from one domain, billed by emails sent with unlimited subscribers. Plans start at $1/mo; free sandbox available.
Researched and fact-checked by Bartu Cavusoglu · Updated October 26, 2026
day3 is an email tool that handles both marketing email and transactional email from one verified domain. Product updates, changelogs, receipts and password resets share a single monthly send allowance. The company bills by emails sent rather than by list size, so every plan includes unlimited subscribers. It is built by Morten Pradsgaard under Pradsgaard Labs EMV in Herning, Denmark, and is hosted in the European Union.
The product is aimed at small software teams that announce things to their users. Its own site says it is the wrong tool for marketing teams running funnels and for agencies managing client accounts, since it has no A/B testing, no CRM and no landing pages. The About page also states that day3 is new and has no third-party reviews yet.
Setup starts with a sending domain. Users can connect Cloudflare, and day3 writes the DKIM, SPF and DMARC records and rechecks them until the domain verifies. Next come a sender and an audience, built by importing contacts or by publishing signup forms as pages, embeds or popups. Campaigns are then drafted in a focused composer.
When a campaign is sent, delivery goes out in batches under a hard monthly cap, with no duplicates if a job retries. A rate limit pauses the send and resumes it automatically. The activity view shows delivered, opened, clicked and bounced events searchable per person, and bad addresses are suppressed automatically. Each email to each subscriber counts as one send.
Beyond campaigns, day3 includes automations: a canvas where users draw triggers, emails, waits and branches so each new signup moves through a welcome series on its own. Automations are unlimited on every plan, though the app labels them an early preview. An AI assistant drafts from a brief, suggests subject lines and rewrites selected copy, and it is included on every paid plan.
For developers, a bearer-key JSON API covers transactional email, contacts, audiences and campaigns. An Idempotency-Key header means retries cannot send an email twice, and contacts can be created or updated in one upsert call. day3 also runs an MCP server, so editors such as Claude Code, Cursor and VS Code can draft campaigns. Mailing a real audience through MCP needs the owner's approval.
day3 is an email tool that handles marketing email and transactional email from one verified domain. It is billed by the number of emails sent, and every plan includes unlimited subscribers. It is built by Morten Pradsgaard under Pradsgaard Labs EMV in Denmark.
Plans start at $1/mo for 1,000 emails and go to $220/mo for 1,000,000 emails. Intermediate tiers are $3 for 5,000, $5 for 10,000, $8 for 25,000, $14 for 50,000, $25 for 100,000, $60 for 250,000 and $115 for 500,000 emails. Subscribers are free and unlimited on every plan.
Yes. The free Sandbox plan lets you set up domains, senders, audiences, forms and drafts, with up to 500 subscribers and 100 real sends a month to your own team. No credit card is required. A paid plan is needed to email everyone else.
One email to one subscriber is one send, so a campaign to 1,000 people uses 1,000 emails. Transactional emails and emails sent by automations count the same way. Test sends also count because they go through the real pipeline.
You cannot go over. Sending pauses at the monthly cap with no surprise charge, and moving up a plan resumes sending immediately. Unused emails do not roll over to the next billing period.
It connects to Cloudflare for automatic DNS records and to Claude Code, Cursor and VS Code through its MCP server. It also offers a JSON API and webhooks. The sources do not name other third-party integrations.
The site targets startups, indie developers, SaaS teams and EU companies that send product updates and transactional email. It says it is the wrong tool for marketing teams running funnels and for agencies managing client accounts.
Often, when you email your list less than once a month on average. For example, 10,000 users emailed twice a month is $8/mo. The site notes that a small list emailed daily, such as 1,000 people, can cost less on a per-subscriber plan.