# coss.com vs MailerSend (https://coss.com/compare/mailersend)

> MailerSend is a transactional email API with SMS in the US and Canada. coss.com adds contacts, broadcasts and sub-accounts on the same key.

MailerSend covers transactional email well: an API and SMTP relay, a drag-and-drop builder, inbound routes on every plan, and SMS and WhatsApp as extras. For newsletters it points you to MailerLite. coss.com keeps transactional and marketing email in one account, gives platforms sub-accounts with their own reputation, and logs every request and webhook on every plan.

Facts about MailerSend checked on 2026-11-03 against the sources listed below.

## At a glance

| | coss.com | MailerSend |
| --- | --- | --- |
| Pricing model | Per recipient, with no volume tiers to pick: $0.40 per 1,000 recipients for the first 1,000,000; $0.30 per 1,000 recipients from 1,000,001 to 10,000,000; $0.22 per 1,000 recipients beyond 10,000,000. Paid plans start at $25/month, all of it spendable on usage | Hobby $7/month for 5,000 emails; Starter from $35/month and Professional from $110/month for 50,000; extra emails $1.50 per 1,000 on Hobby, $1.30 on Starter and Professional at 50,000 |
| Free tier | Free plan: 3,000 email recipients a month, 3,000 received emails a month and 3 inboxes; 1 sending domain | 500 emails a month, 1 domain, 1 template, 100 API requests a day, 1 day of activity data; a credit card is required |
| Transactional email | REST API and an SMTP relay (smtp.coss.com), batch and scheduled sends, idempotency keys, templates with versions and locales | Email API and SMTP relay; drag-and-drop, HTML and rich-text builders, dynamic templates and split testing; bulk emailing from Hobby |
| Marketing email | Contacts with custom properties, audiences, segments, topics with a hosted preference center and double opt-in, broadcasts on a separate marketing stream | Built for transactional email: its help pages recommend MailerLite for newsletters and campaigns |
| Receiving email | Every environment has its own address under coss.com's inbound domain, or receive at your own domain with one MX record; an email.received webhook, content and attachments through the API | Inbound routes on every plan: an @inbound.mailersend.net address or your domain with an MX record; messages parsed to JSON, posted to a webhook or forwarded by email |
| SMS | SMS (US): $0.0142 per segment; SMS (other countries): $0.022 to $0.1134 per segment, carrier fees included; live SMS on paid plans. The US and Canada by default; others once you allow them, from the priced list on coss.com/pricing | US and Canada only, transactional only; 100 messages a month on Starter, 150 on Professional, then $1.40 per 100; phone numbers $2 each |
| WhatsApp | — | An add-on on Hobby, Starter and Professional |
| Multi-tenant sending | Sub-accounts on Scale and Enterprise: each with its own domains, SES tenant, reputation, quotas and suppression list (transactional email) | 1 domain on Hobby, 10 on Starter, unlimited on Professional, with extra domains at $4; no sub-accounts on its pricing page |
| Dedicated IPs | An add-on on Scale and Enterprise: Amazon SES managed dedicated IPs, warmed up automatically | An add-on for Enterprise accounts sending over 100,000 emails a week |
| Activity history | Every API request, email event and webhook attempt of an environment, searchable and exportable; log drains on Scale and Enterprise | 1 day on Free and Hobby, 7 days on Starter, 30 days on Professional; up to 365 days as an add-on, from $5 |
| Webhooks | Standard Webhooks signatures, automatic retries, test events and `coss listen` to forward events to localhost | HMAC-SHA256 of the body in a Signature header; retries for about 3 days; 1 webhook on Free and Hobby, 50 on Starter, unlimited on Professional |
| SDKs | TypeScript, plus generated SDKs for Python, Go, Ruby, PHP, Java and .NET; Laravel, Rails and Django mail drivers; a CLI and an MCP server | Node.js, Python, Java, Laravel, PHP, Go and Ruby; a CLI and an MCP server |

## When MailerSend is the better choice

- **Designers build your emails.** MailerSend has drag-and-drop, HTML and rich-text builders and split testing. coss.com templates are HTML and text with variables, edited in the dashboard or through the API.
- **You need WhatsApp.** WhatsApp is an add-on on MailerSend's paid plans. coss.com doesn't send WhatsApp messages.
- **You want verification and blocklist tools.** MailerSend sells email verification credits on every plan and includes blocklist monitoring. coss.com has email checks in Risk and DMARC reports, but no blocklist monitoring.
- **You send a small, steady volume.** Hobby is a flat monthly fee for 5,000 emails, for a single domain.

## When coss.com is the better choice

- **Newsletters from the same account.** Contacts, audiences, segments, topics with a hosted preference center and broadcasts live next to your transactional email, on a separate stream with its own reputation.
- **You send for your own customers.** Sub-accounts on Scale and Enterprise each get their own domains, SES tenant, reputation, quotas and suppressions, and pause on their own bounces and complaints, not yours.
- **SMS beyond North America, or for marketing.** MailerSend's SMS is US and Canada, and transactional only. coss.com can send to other priced countries once you allow them, and its registration form has a marketing use case.
- **Logs on every plan.** Each environment's log holds every API request, email event and webhook attempt, Free included, instead of a retention window chosen by plan.
- **Sandbox environments.** Sandbox environments with coss_test_ keys are free, run the same API, send nothing and simulate outcomes for email and SMS.

## Moving from MailerSend

1. **Add and verify your domains.** There is no importer for MailerSend: the dashboard's importer covers Resend, SendGrid and Postmark. Add each domain in coss.com and publish its DNS records. coss.com's DKIM records sit next to MailerSend's, so you can keep sending there until you switch. (/docs/email/domains)
2. **Bring over suppressions.** Page through MailerSend's hard bounce, spam complaint, unsubscribe and blocklist endpoints and import the addresses with coss.email.suppressions.import, or as CSV on the Suppressions page. (/docs/email/suppressions)
3. **Recreate your templates.** Recreate each template in coss.com's template language, declare its variables, publish it and send it with template_id and variables. Or send HTML or React Email from your code. (/docs/email/templates)
4. **Switch sending, routes and webhooks.** Send with coss.email.send() or SMTP at smtp.coss.com. Replace inbound routes with a receiving domain and an email.received handler, and point webhook handlers at coss.com's events and signatures. SMS needs a coss.com number and its own registration. (/docs/email/receiving)

## Frequently asked questions

### Is there an importer for MailerSend?

No. The dashboard's importer covers Resend, SendGrid and Postmark. From MailerSend, add your domains, import your suppressions through the API or as CSV, recreate your templates and switch your sending code or SMTP settings.

### Can coss.com send newsletters as well as transactional email?

Yes. Broadcasts and marketing sends use the same API key and SDK as transactional email, on a separate stream with its own reputation, so newsletter complaints never hold up password resets.

### Does coss.com have inbound routing like MailerSend?

coss.com receives every message for an environment's addresses, stores it and sends an email.received webhook; your code decides what to do with it. There are no route rules or forwarding to another address.

### Can coss.com send SMS outside the US and Canada?

Yes. Every organization starts with the US and Canada, and owners and admins can allow other priced countries. The numbers themselves are US and Canadian, and toll-free numbers only send to those two countries.

### Does coss.com work with SMTP like MailerSend?

Yes. smtp.coss.com accepts TLS on port 465 and STARTTLS on 587 (2465 and 2587 also work), with the username coss and an API key as the password.

## Sources

- [MailerSend pricing](https://www.mailersend.com/pricing)
- [MailerSend: transactional and marketing email](https://www.mailersend.com/help/transactional-email-vs-marketing-email)
- [MailerSend: inbound email](https://www.mailersend.com/whats-new/inbound-emails)
- [MailerSend docs: inbound routing](https://developers.mailersend.com/api/v1/inbound.html)
- [MailerSend SMS API](https://www.mailersend.com/features/sms-api)
- [MailerSend docs: webhooks](https://developers.mailersend.com/api/v1/webhooks.html)
- [MailerSend docs](https://developers.mailersend.com/)
- [MailerSend CLI](https://developers.mailersend.com/tools/cli)
- [MailerSend MCP server](https://developers.mailersend.com/mcp)