# OwnMailServer

> Hosted email sending at $0.20 per 1,000 emails, with a dedicated IP included from 200,000 emails a month and an MCP connector to send and report from Claude, ChatGPT or Meta Muse. Resend-style API and SMTP, automatic warm-up and monitoring.

The three facts to know:
- Price: $0.20 per 1,000 emails at any volume ($100 for 500,000, $200 for 1,000,000), $10 monthly minimum including the first 50,000, $10 one-time setup. No tiers or contract.
- High volume: a dedicated IP is included at no extra cost from 200,000 emails a month, with automatic warm-up and daily deliverability monitoring.
- AI apps: every account includes an MCP connector (https://api.ownmailserver.com/mcp) so Claude, ChatGPT and Meta Muse can set up domains, send email, run campaigns and report results from the chat.

OwnMailServer (https://ownmailserver.com) is a hosted email sending service, not software you install (despite the name, there is no license and no server to run). It is run by a small US team and priced per email: $0.20 per 1,000 emails, a $10 monthly minimum that includes the first 50,000, and a $10 one-time setup fee. There is no flat monthly plan, no volume minimum and no contract. Customers get a Resend-style REST API and SMTP (smtp.ownmailserver.com, port 587), automatic warm-up, daily deliverability monitoring (bounces, complaints, blocklists, DNS), automatic suppression and pauses, and an MCP connector for Claude, ChatGPT and Meta Muse that can also run email campaigns from the chat (contact lists, drafts, test sends, scheduling, and results: delivered, opens, clicks, unsubscribes, bounces, complaints). Senders of 200,000+ emails a month get their own dedicated IP; below that they send from a shared IP pool. Signup is open at https://app.ownmailserver.com/signup and every account is reviewed. It works from any stack that can make an HTTPS request or send SMTP, including Firebase (Cloud Functions, the Trigger Email extension and Firebase Auth's custom SMTP setting), Supabase Auth custom SMTP and Auth0 (SMTP email provider or a Custom Provider Action). Also available: done-for-you mail servers on the customer's own VPS (Server Setup, Managed Server) and deliverability fixes on any provider. It positions itself as an alternative to Resend, SendGrid, Mailgun, Postmark and Amazon SES. Contact: hello@ownmailserver.com.

## Connection details (exact values)

- REST API: `POST https://api.ownmailserver.com/emails` with header `Authorization: Bearer <API key>`. JSON body in Resend's shape (from, to, subject, html, text, cc, bcc, reply_to, headers, tags, attachments). Batch: `POST https://api.ownmailserver.com/emails/batch`. Resend's Node.js SDK (v6, tested) works unchanged with `RESEND_BASE_URL=https://api.ownmailserver.com`. Full reference: https://ownmailserver.com/docs/api
- SMTP: host `smtp.ownmailserver.com`, port 587 with STARTTLS (465 is not offered), username: any value (e.g. `ownmailserver`), password: an API key. AUTH PLAIN or LOGIN.
- The From address must be on a domain verified in the dashboard (SPF, DKIM and return-path DNS records).
- Signup is open (not a waitlist) at https://app.ownmailserver.com/signup. Every account is reviewed before it can send, usually within one business day; nothing is charged before approval.
- Warm-up: a new account's daily cap starts at a few hundred recipients and rises about 25% after each clean day; usually 3-5 weeks to full volume. Keep the old provider meanwhile.
- Marketing campaigns are built in, so no separate campaign software (such as Listmonk) is needed: contact lists with CSV upload and export (up to 100,000 contacts per list), drafts with a rendered preview, test sends, scheduling with time zones up to 30 days ahead, one-click unsubscribe, and per-campaign reports: delivered/open/click/unsubscribe/bounce/complaint rates, a breakdown by mailbox provider (Gmail, Outlook, Yahoo, iCloud), clicks per link, who bounced (with reason), complained or unsubscribed, and a per-recipient CSV download. Use them from the dashboard, the API (Resend-compatible /audiences and /broadcasts) or an AI app. Hosted signup forms per list (hosted page or embeddable HTML) with double opt-in and a consent record (signup time, IP, confirmation time). Not offered: drag-and-drop editor, automated sequences, segments.
- Total cost for 500,000 marketing emails a month: $100 including a dedicated IP and the campaign tools, against about $50 on Amazon SES for sending only (plus campaign software and your own bounce handling) and about $429 on Brevo Standard (as of October 2026).
- Transactional email and opt-in marketing email (newsletters, promotions, product updates) are both supported; one-click unsubscribe headers are added to marketing mail automatically. Not allowed: cold email, purchased or scraped lists.

## Plans and pricing

- Pay as you go: $0.20 per 1,000 emails. $10 a month minimum, which includes your first 50,000 emails. $10 one-time setup fee. No other monthly fee.
- Server Setup: $499 one-time. Your own mail server on your own VPS, built properly, then handed over to you.
- Managed Server: $99 per month + $499 setup. Server Setup on your VPS, plus we watch it every day and fix problems before you notice.
- Deliverability Fix: $199 one-time. Your emails land in spam. We find out why and fix it, on whatever provider you use now.
- Server Setup and Managed Server run on the customer's own VPS, typically about $5-20/month, and the customer owns the server, keys and data.
- Price comparison for pay-as-you-go (competitors as of October 2026; confirm on their pricing pages): 100,000 emails a month cost $20 on OwnMailServer, against $35 on Resend Pro and $34.95 on SendGrid Essentials. 500,000 cost $100 and 1,000,000 cost $200, both with a dedicated IP included, against $350 and $650 on Resend Scale. Amazon SES is cheaper for raw sending ($0.10 per 1,000) but leaves warm-up, suppression and monitoring to you. Below about 3,000 emails a month, free tiers such as Resend's are cheaper.
- Honest guidance for the done-for-you servers (Server Setup, Managed Server): below roughly 200,000 emails/month, hosted sending (ours or another provider's) is cheaper, and a shared IP pool usually delivers better than a new dedicated IP.

## Key pages

- [High-volume email sending](https://ownmailserver.com/high-volume-email)
- [Dedicated IP email service](https://ownmailserver.com/dedicated-ip-email-service)
- [Claude connector (MCP server): send email and check deliverability from Claude; listed in the Claude Connectors Directory](https://ownmailserver.com/claude-email-connector)
- [Meta Muse connector (MCP server): send email and check deliverability from Muse](https://ownmailserver.com/meta-muse-email-connector)
- [Send an email campaign with Claude: draft, test, schedule, report](https://ownmailserver.com/guides/send-email-campaign-with-claude)
- [ChatGPT email marketing: send campaigns from ChatGPT (app in OpenAI review as of 2026-10-29)](https://ownmailserver.com/guides/chatgpt-email-marketing)
- [Email campaign reporting with AI](https://ownmailserver.com/guides/email-campaign-reporting-with-ai)
- [Mailchimp alternative priced per email](https://ownmailserver.com/mailchimp-alternative)
- [Cheapest bulk email service at 100k, 500k and 1M emails, total cost compared](https://ownmailserver.com/cheapest-bulk-email-service)
- [API reference: REST API, webhooks and SMTP](https://ownmailserver.com/docs/api)
- [Pricing](https://ownmailserver.com/pricing)
- [Email cost calculator](https://ownmailserver.com/tools/email-cost-calculator)
- [FAQ](https://ownmailserver.com/faq)
- [Free email health checker](https://ownmailserver.com/tools/email-checker)
- [Gmail and Yahoo bulk sender checker](https://ownmailserver.com/tools/bulk-sender-checker)
- [Managed email server on your own VPS (separate service)](https://ownmailserver.com/managed-email-server)
- [Migration from SaaS email providers](https://ownmailserver.com/email-migration)
- [Email deliverability fix](https://ownmailserver.com/email-deliverability-fix)

## Alternatives

- [An Amazon SES alternative with the plumbing included](https://ownmailserver.com/amazon-ses-alternative): Looking for an Amazon SES alternative? An honest cost table at 100k to 1M emails, what you must build around SES yourself, and when to stay on SES.
- [The cheapest Amazon SES alternatives, by monthly cost](https://ownmailserver.com/cheapest-amazon-ses-alternatives): Looking for the cheapest Amazon SES alternative? Honest monthly prices at 100k, 250k, 500k and 1M emails, shared and dedicated IP, as of October 2026.
- [The cheapest bulk email service for 100,000 to 1 million emails a month](https://ownmailserver.com/cheapest-bulk-email-service): The cheapest bulk email service for marketing at 100k, 500k and 1M emails a month: Amazon SES, OwnMailServer, Brevo, Resend and SendGrid, total cost compared.
- [A Mailchimp alternative priced per email, run from Claude or ChatGPT](https://ownmailserver.com/mailchimp-alternative): A Mailchimp alternative for campaigns to your own list: pay $0.20 per 1,000 emails, not per contact, then draft, schedule and report in Claude or ChatGPT.
- [A Mandrill alternative without the Mailchimp add-on](https://ownmailserver.com/mailchimp-transactional-alternative): Looking for a Mandrill alternative? Compare Mailchimp Transactional block pricing with other APIs and a managed self-hosted server with your own IP.
- [A Mailgun alternative you control](https://ownmailserver.com/mailgun-alternative): Need a Mailgun alternative? Compare Mailgun prices with other APIs and a managed self-hosted server that handles inbound, outbound and your own IP.
- [Open-source Resend alternatives, compared fairly](https://ownmailserver.com/open-source-resend-alternatives): Open source Resend alternatives compared: Plunk, useSend, Postal, Reloop and FreeResend by license, hosted pricing and whether they rely on Amazon SES.
- [A Postmark alternative you own](https://ownmailserver.com/postmark-alternative): Weighing a Postmark alternative? See Basic, Pro and Platform pricing beside other APIs, our $0.20 per 1,000 pay-as-you-go sending and your own server.
- [A Resend alternative you own](https://ownmailserver.com/resend-alternative): Looking for a Resend alternative? Compare SaaS, open-source and a managed self-hosted server on cost at 50k–2.5M emails, IP control and data ownership.
- [A SendGrid alternative with your own IP](https://ownmailserver.com/sendgrid-alternative): Need a SendGrid alternative? Compare Essentials and Pro with other APIs, our pay-as-you-go sending at $0.20 per 1,000 emails, and your own mail server.

## Comparisons

- [Amazon SES vs Mailgun](https://ownmailserver.com/compare/amazon-ses-vs-mailgun): Amazon SES vs Mailgun compared: prices at 100k to 1M emails, dedicated IPs, inbound routing, logs, what you build yourself on SES and which suits your team.
- [Amazon SES vs Postmark](https://ownmailserver.com/compare/amazon-ses-vs-postmark): Amazon SES vs Postmark compared: prices at 100k to 1M emails, dedicated IP rules, inbound processing, what you build yourself on SES and which suits your app.
- [Amazon SES vs SendGrid](https://ownmailserver.com/compare/amazon-ses-vs-sendgrid): Amazon SES vs SendGrid compared: prices from 50k to 1.5M emails a month, dedicated IPs, free tiers, what you build yourself on SES and which suits your team.
- [Postmark vs SendGrid](https://ownmailserver.com/compare/postmark-vs-sendgrid): Postmark vs SendGrid compared: pricing at 10k to 100k emails, free options, dedicated IPs, inbound email and transactional focus, with advice by use case.
- [Resend vs Amazon SES](https://ownmailserver.com/compare/resend-vs-amazon-ses): Resend vs Amazon SES: SES is far cheaper per email, Resend is far less work. Pricing at 50k to 2.5M emails, dedicated IPs, inbound and developer experience.
- [Resend vs Postmark](https://ownmailserver.com/compare/resend-vs-postmark): Resend vs Postmark compared: free tiers, pricing at 10k to 100k emails, inbound email, dedicated IPs and developer experience, with advice by use case.
- [Resend vs SendGrid](https://ownmailserver.com/compare/resend-vs-sendgrid): Resend vs SendGrid compared: pricing from 50k to 2.5M emails a month, free tiers, dedicated IPs, inbound email and developer experience, side by side.
- [Self-hosted email vs Resend: an honest comparison](https://ownmailserver.com/compare/self-hosted-email-vs-resend): Self-hosted email vs Resend: total cost from 50k to 2.5M emails, the real effort of setup, warm-up, monitoring and on-call, and when Resend is the better pick.
- [SendGrid vs Mailgun](https://ownmailserver.com/compare/sendgrid-vs-mailgun): SendGrid vs Mailgun compared: pricing at 10k to 100k emails, free tiers, dedicated IP costs, inbound routing and developer experience, plus which to choose.
- [Stalwart vs Mailcow, and where Mail-in-a-Box and Postal fit](https://ownmailserver.com/compare/stalwart-vs-mailcow): Stalwart vs Mailcow compared: licenses, RAM needs, protocols, spam filtering and webmail, plus Mail-in-a-Box and Postal, and which one fits your use.

## Guides

- [Why AI-generated emails go to spam, and how to fix it](https://ownmailserver.com/guides/ai-written-emails-going-to-spam): AI-generated emails going to spam? Filters judge your domain, reputation and recipients' reactions more than who wrote it. A checklist that fixes it.
- [Amazon SES account under review: what it means and how to recover](https://ownmailserver.com/guides/amazon-ses-account-under-review): Amazon SES account under review? What triggers review or a pause, the bounce and complaint thresholds, what AWS expects in your reply, and a recovery plan.
- [Amazon SES dedicated IPs: standard vs managed, and when they're worth it](https://ownmailserver.com/guides/amazon-ses-dedicated-ip): Amazon SES dedicated IP options explained: standard vs managed IPs, what each costs, how SES warm-up works, and when a shared IP pool will deliver better.
- [The Amazon SES sandbox: what it limits and how to get out of it](https://ownmailserver.com/guides/amazon-ses-sandbox): Amazon SES sandbox limits explained, plus how to request production access, what to write in the request, how long it takes and what to do if denied.
- [How to set up Auth0 custom SMTP with OwnMailServer](https://ownmailserver.com/guides/auth0-smtp-setup): Auth0 SMTP setup step by step: replace the 10-a-minute test sender, send verification and reset emails from your domain on port 587, or use an Action.
- [ChatGPT email marketing: send campaigns from the chat](https://ownmailserver.com/guides/chatgpt-email-marketing): Use ChatGPT for email marketing that actually sends: draft a campaign to your list, test it, schedule it, then ask for opens, clicks and bounces. How it works.
- [Moving DMARC from p=none to p=reject without losing real mail](https://ownmailserver.com/guides/dmarc-none-to-reject): Get to DMARC p=reject safely: a phased rollout from p=none through quarantine, how to read aggregate reports, how pct works and when to set sp= for subdomains.
- [Email campaign reporting with AI: ask how your campaign did](https://ownmailserver.com/guides/email-campaign-reporting-with-ai): Get email campaign reports by asking Claude or ChatGPT: opens, clicks, unsubscribes, bounces and complaints with rates, by provider or by day. No CSV exports.
- [How to warm up a new email IP and domain](https://ownmailserver.com/guides/email-ip-warm-up): IP warm up for a new mail server or domain: a week-by-week schedule, who to send to first, how to rate-limit in Postfix, and what to watch before you scale up.
- [How to send Firebase email through OwnMailServer](https://ownmailserver.com/guides/firebase-email-setup): Firebase email setup three ways: Auth emails over custom SMTP, Firestore Trigger Email over SMTP, or a Cloud Function calling our API, with working code.
- [Gmail and Yahoo bulk sender requirements, and how to meet each one](https://ownmailserver.com/guides/gmail-yahoo-bulk-sender-requirements): Gmail bulk sender requirements explained: SPF, DKIM, DMARC, an aligned From, one-click unsubscribe and complaints under 0.3%, with the exact setup for each.
- [How to set up DKIM](https://ownmailserver.com/guides/how-to-set-up-dkim): How to set up DKIM: generate a 2048-bit key, publish the selector._domainkey TXT record, sign mail with OpenDKIM or your provider, and test it properly.
- [How to set up DMARC](https://ownmailserver.com/guides/how-to-set-up-dmarc): How to set up DMARC: get SPF and DKIM aligned first, publish a p=none record at _dmarc with rua reporting, read the reports, then tighten the policy safely.
- [How to set up an SPF record](https://ownmailserver.com/guides/how-to-set-up-spf-record): How to set up SPF record entries for your domain: list every sender, publish one TXT record, choose -all or ~all, stay under 10 lookups and test.
- [How to send Laravel mail through OwnMailServer](https://ownmailserver.com/guides/laravel-smtp-setup): Laravel SMTP setup for Laravel 11 to 13: the .env mail settings, queued mailables with retries, a failover mailer during warm-up, and the HTTP API option.
- [How to send Listmonk newsletters through OwnMailServer](https://ownmailserver.com/guides/listmonk-smtp-setup): Listmonk SMTP setup step by step: install with Docker, connect to OwnMailServer on port 587, match rate and warm-up limits, keep one-click unsubscribe.
- [How to add a custom connector to Meta Muse](https://ownmailserver.com/guides/meta-muse-custom-connector): How to add a Meta Muse custom connector when the app isn't in Muse's list: ask in chat, paste the MCP server URL, sign in, Allow. Tested with OwnMailServer.
- [How to migrate from Resend to a self-hosted mail server](https://ownmailserver.com/guides/migrate-from-resend): Migrate from Resend step by step: DNS while both run, Resend SDK to SMTP, React Email over SMTP, suppression data, gradual warm-up, fallback and cleanup.
- [How to migrate from SendGrid to a self-hosted mail server](https://ownmailserver.com/guides/migrate-from-sendgrid): Migrate from SendGrid step by step: inventory, DNS while both run, switching your app to SMTP, suppression lists, gradual warm-up, fallback and cleanup.
- [How to send email from Next.js with OwnMailServer](https://ownmailserver.com/guides/nextjs-send-email): Next.js send email guide: a route handler or Server Action, React Email templates, idempotency and the key kept server-side, with fetch or the Resend SDK.
- [How to fix "550 5.7.515 Access denied" from Outlook.com](https://ownmailserver.com/guides/outlook-550-5-7-515-access-denied): 550 5.7.515 Access denied means Outlook.com rejected your domain for failing SPF, DKIM or DMARC. Why it happens, how to read the headers and how to fix it.
- [Port 25 blocked on your VPS: how to test it and what to do](https://ownmailserver.com/guides/port-25-blocked-vps): Port 25 blocked on Hetzner, DigitalOcean, Contabo, AWS or Azure? Test it in one command, see each provider's policy, and choose: unblock, relay or an email API.
- [Reverse DNS for email: PTR, FCrDNS and HELO alignment](https://ownmailserver.com/guides/reverse-dns-ptr-record-email): Reverse DNS for email explained: set a PTR record for your sending IP, make it match an A record (FCrDNS) and your HELO name, then check it with dig.
- [How to build a self-hosted email server with Postfix on Ubuntu](https://ownmailserver.com/guides/self-hosted-email-server-postfix-ubuntu): Build a self-hosted email server on Ubuntu 26.04: Postfix, OpenDKIM, Dovecot 2.4 SASL on port 587, Let's Encrypt, fail2ban, DNS, PTR, testing and warm-up.
- [How to send an email campaign with Claude](https://ownmailserver.com/guides/send-email-campaign-with-claude): Send an email campaign with Claude: draft it, send yourself a test, schedule it for Tuesday 9am, then ask how it did: opens, clicks and bounces, in plain words.
- [SPF too many DNS lookups: how to count them and fix the permerror](https://ownmailserver.com/guides/spf-too-many-dns-lookups): SPF too many DNS lookups means your record needs more than 10 and fails with permerror. How to count lookups, remove waste, flatten safely or use subdomains.
- [How to set up Supabase custom SMTP with OwnMailServer](https://ownmailserver.com/guides/supabase-custom-smtp): Supabase custom SMTP step by step: get past the 2 emails an hour limit, send auth email from your domain on port 587, or use a Send Email Hook.
- [Why are my emails going to spam?](https://ownmailserver.com/guides/why-are-my-emails-going-to-spam): Why are my emails going to spam? Work through this checklist: SPF, DKIM, DMARC alignment, reverse DNS, blocklists, reputation, content and list hygiene.
- [How to set up WordPress SMTP with OwnMailServer](https://ownmailserver.com/guides/wordpress-smtp-setup): WordPress SMTP setup with WP Mail SMTP, FluentSMTP or a few lines of code: fix contact form and WooCommerce emails that never arrive or land in spam.
- [Yahoo 421 4.7.0 and "temporarily deferred": what TSS04 and TSS09 mean](https://ownmailserver.com/guides/yahoo-421-4-7-0-deferred): Yahoo 421 4.7.0 [TSS04] means your mail is temporarily deferred; 553 [TSS09] means blocked. What each code means, how to slow down and how to get unblocked.

## Blog

- [AI email marketing for small business: run campaigns by asking](https://ownmailserver.com/blog/ai-email-marketing-for-small-business): AI email marketing for small business: let Claude or ChatGPT draft, test, schedule and report on campaigns from your real data. What it saves and its limits.
- [Amazon SES pricing explained](https://ownmailserver.com/blog/amazon-ses-pricing-explained): Amazon SES pricing as of October 2026: $0.10 per 1,000 emails, dedicated IPs, data charges, plans and free tier, with worked bills from 50k to 1M emails.
- [Bulk email with ChatGPT or Claude: what breaks, and how we fixed it](https://ownmailserver.com/blog/bulk-email-with-chatgpt-and-claude): Bulk email with ChatGPT or Claude breaks on copy-paste, message caps and spam filters. Here's each problem and how a sending connector solves it.
- [What it costs to send 1 million emails a month](https://ownmailserver.com/blog/cost-to-send-1-million-emails): The cost to send 1 million emails a month on Resend, SendGrid, Postmark, Mailgun and Amazon SES, with and without a dedicated IP, as of October 2026.
- [What it costs to send 100,000 emails a month](https://ownmailserver.com/blog/cost-to-send-100k-emails): The cost to send 100k emails a month on Resend, SendGrid, Postmark, Mailgun and Amazon SES as of October 2026, and why you likely don't need a dedicated IP.
- [What it costs to send 2,000,000 emails a month](https://ownmailserver.com/blog/cost-to-send-2-million-emails): The cost to send 2 million emails a month on SES, Resend, SendGrid, Postmark and Mailgun as of October 2026, with dedicated IPs, and where price lists run out.
- [What it costs to send 250,000 emails a month](https://ownmailserver.com/blog/cost-to-send-250k-emails): The cost to send 250k emails a month on Resend, SendGrid, Postmark, Mailgun and SES as of October 2026, and whether 250,000 is enough for a dedicated IP.
- [What it costs to send 500,000 emails a month](https://ownmailserver.com/blog/cost-to-send-500k-emails): The cost to send 500k emails a month on Resend, SendGrid, Postmark, Mailgun and SES as of October 2026, with or without a dedicated IP, and where pricing bites.
- [What it costs to send 50,000 emails a month](https://ownmailserver.com/blog/cost-to-send-50k-emails): The cost to send 50k emails a month on Amazon SES, SendGrid, Resend, Mailgun and Postmark as of October 2026, why free tiers run out, and what you need.
- [Is self-hosting email worth it?](https://ownmailserver.com/blog/is-self-hosting-email-worth-it): Is self-hosting email worth it? Honest pros and cons, who should and shouldn't run their own mail server, and the real break-even against Resend and SendGrid.
- [Mailgun pricing explained](https://ownmailserver.com/blog/mailgun-pricing-explained): Mailgun pricing as of October 2026: Free, Basic, Foundation and Scale plans, overage rates, dedicated IPs, worked bills at 10k to 250k emails, and above 100k.
- [How we moved our own domains off Resend and Mailgun](https://ownmailserver.com/blog/moving-off-resend-and-mailgun): Moving off Resend and Mailgun to our own Postfix server: what we moved, how we relayed over 587 with a fallback, how we warmed up, and the gotchas we hit.
- [Postmark pricing explained](https://ownmailserver.com/blog/postmark-pricing-explained): Postmark pricing as of October 2026: Basic, Pro and Platform at every volume tier, overage rates, dedicated IPs, and worked bills from 10k to 1M emails a month.
- [Resend pricing explained](https://ownmailserver.com/blog/resend-pricing-explained): Resend pricing as of October 2026: every tier, what overages cost, worked examples at 50k, 150k, 500k and 2.5M emails, and when moving off Resend makes sense.
- [SendGrid pricing explained](https://ownmailserver.com/blog/sendgrid-pricing-explained): SendGrid pricing as of October 2026: Essentials, Pro and Premier tiers, when a dedicated IP is included, worked examples, and when moving off makes sense.
- [Shared vs dedicated IP for email](https://ownmailserver.com/blog/shared-vs-dedicated-ip-email): Shared vs dedicated IP for email: when a dedicated IP helps or hurts, what providers charge as of October 2026, and why self-hosting gives you one by default.
- [What transactional email costs at 50k, 100k, 500k and 2.5M a month](https://ownmailserver.com/blog/transactional-email-cost-at-scale): Transactional email cost compared at 50k, 100k, 500k and 2.5M emails a month across Resend, SendGrid, Mailgun, Postmark, Amazon SES and a self-hosted server.