AuthSMTP
Global outgoing SMTP email service
About AuthSMTP
AuthSMTP is an authenticated outgoing SMTP relay for websites, e-commerce stores, mailing lists, mail servers, and desktop or mobile email clients. You point any SMTP-capable app at its servers with a username and password, and it handles delivery, reputation monitoring, and blacklist tracking. Plans are billed annually by monthly message quota, from 2,000 to 2 million emails per month.
Pros & Cons
Pros
- Low entry price: $72 per year covers 2,000 emails per month
- Monthly quotas instead of daily caps, which suits bursty sending
- Works with almost any SMTP-capable app, server, or email client with no code changes
- Free dedicated IP on request from the 50,000-message plan up
- Long track record: the service has run since 2003
- Money-back guarantee on new accounts
Cons
- No free tier or free trial plan
- Annual billing only; no monthly payment option
- The REST API is mostly account and quota reporting; HTTP message sending is still in beta
- Few independent reviews, with mixed feedback on deliverability and support
- Dated control panel and documentation compared with developer-first email APIs
Key Features
Authenticated SMTP server
Send from any program, app, server, or device that supports SMTP authentication, from home, office, mobile, or public Wi-Fi connections.
Multiple from addresses and domains
Send from 20 to 600 verified sender addresses or domains depending on plan, with strict sender validation.
SSL/TLS and alternative ports
Encrypted SMTP authentication and transport, plus a choice of alternative SMTP ports for networks that block port 25.
SPF and DKIM support
Sender authentication support to help prevent spoofing and improve inbox placement.
Shared or dedicated IP
Smaller plans send from monitored shared IPs; plans from 50,000 messages per month can request a dedicated IP at no extra cost.
Bounce and complaint reporting
Spam complaint and bounce reporting, blacklist monitoring, and ISP feedback loops, visible in the online control panel.
Virus scanning and email backup
Outgoing messages are virus scanned, with optional email duplication for backup copies.
Instant quota upgrades
Boost or upgrade the monthly message allowance from the control panel with no automatic overage billing.
Account API
HTTPS REST API that returns account details, quota usage, and dedicated IP allocation in XML; a message submission API is in beta.
Large message support
Accepts emails up to 50 MB with multiple concurrent connections.
Pricing
- 2,000 messages per month
- 600 MB data per month
- 20 from addresses/domains
- Shared IP address
- 10,000 messages per month
- 3 GB data per month
- 100 from addresses/domains
- Shared IP address
- 50,000 messages per month
- 15 GB data per month
- 500 from addresses/domains
- Dedicated IP on request
- 100,000 messages per month
- 30 GB data per month
- 600 from addresses/domains
- Dedicated IP on request
- 2 million messages per month
- 600 GB data per month
- 600 from addresses/domains
- Dedicated IP on request
Best For
E-commerce order emails
Route order confirmations and shipping notifications from a web store through a monitored SMTP relay instead of the web host's mail server.
Sending from email clients on any network
Small businesses and sole traders send from Outlook, Apple Mail, or phones through one authenticated server when ISPs block port 25.
Relaying from on-premises mail servers
Exchange or UNIX mail servers relay outbound mail through AuthSMTP to improve deliverability and avoid blacklisted IPs.
Application and mailing list delivery
Web apps and mailing list software send transactional and bulk messages within a fixed annual quota.
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