Routing & failover

Your providers, behind one endpoint.

Connect the accounts you already have and order the chain. A timeout or an empty credit balance becomes a reroute — not a missing email.

Email provider failover means a timeout, rate limit, or exhausted account at one provider doesn't stop your mail: the gateway reads the error, classifies it, and reroutes the message to the next provider in your chain — automatically, mid-send. Hard bounces are the exception: those are suppressed instead of retried, so a bad address never hurts your sender reputation twice.

Mailway supports four routing strategies per project — failover, free-first, round-robin, and random — over the provider accounts you already own (supported providers). Free-first spends each provider's free tier before a single paid send; the calculator below shows what that does to a monthly bill.

02 · Routing & Failover

Providers fail.
Your email shouldn't.

Your app hands off once, gets 250 OK, and moves on. Mailway reads whatever the provider says back — a timeout, a rate limit, an empty credit balance — and reroutes in milliseconds. Here's a genuinely bad day, handled without a single page going out:

Your Appsmtp.mailway.netSMTPROUTES · LOGS · FAILS OVERAmazon SES421 timeoutSendGrid401 credits exhaustedMailgun250 accepted · 97ms

Four routing strategies

reliability
Failover

Primary provider first. On timeout, rate limit, or outage, the next one takes over automatically — with exponential backoff.

cost
Free-first

Spend every provider's free tier before a single paid send — paid rates only kick in once the free capacity is gone. Exhausted providers stay available for failover.

balance
Round-robin

Distribute volume evenly across providers. Balance spend, spread sender reputation, and stay under per-provider rate limits.

simplicity
Random

A coin flip per message. For when you want the volume spread and nothing else to think about.

Not all errors are equal

provider saysclassmailway does
550 user not foundhard bouncestop · suppress · log
401 credits exhaustedbilling / quotafailover · flag the account
429 rate limitedsoft bouncefailover to next provider
421 timeoutconnectionfailover with backoff

Hard bounces are never retried — the address goes straight to your suppression list, where it stops hurting your sender reputation. Everything recoverable fails over. Nothing gets retried into a blocklist.

Cost optimization

Drag the slider.
Watch the savings.

The free-first routing strategy fills every provider's free tier before a single paid send — a paid rate only kicks in once all the free capacity is spent. You pay providers directly at their prices — Mailway takes zero margin on delivery, because we never touch it.

1K10,000200K
Providers configured
Amazon SES$0.10/1K
Resend100 free/day
Mailgun5K free/mo
Mailtrap4K free/mo
Brevo300 free/day
MailerSend500 free/mo
Postmark100 free/mo
SES only — single providerno failover
$1.00/month
10,000 emails via SES at $0.10/1K
SAVES 100%
Free-first — 7 providers+ failover
$0.00/month
SES paid overflow0
Resend free0
Mailgun free0
Mailtrap free0
Brevo free0
MailerSend free0
Postmark free0
Free tiers cover all 10,000 emails. $0.00 — you save the full $1.00/month vs SES-only.

provider free tiers as documented · you pay providers directly · mailway never marks up provider cost

Your mailer config has
one line to change

Mailway is in private beta — we onboard teams one at a time. Leave your email and we'll send your invite when it's your turn.

read the docs meanwhile →

join the waitlist — mailway.net

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Mailway is in private beta — we onboard teams one at a time, in order. Leave your email and yours arrives when it's your turn.