MailerZ documentation

From domain to dependable delivery.

Clear setup instructions for forwarding, SMTP sending, DNS, recovery and limits—written for people who do not live in email headers.

Start here

One path from zero to working

01

Add and verify a domain

Prove domain control with the unique TXT record, then wait for a successful verification check.

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02

Configure MX records

Point inbound mail to the exact hosts and priorities shown in your dashboard.

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03

Create aliases and destinations

Map sales@, support@ or any named address to one or more real inboxes.

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04

Configure catch-all

Choose what happens to addresses you did not create: forward or hold for review.

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05

Connect SMTP

Use a generated credential and encrypted SMTP to send from your verified domain.

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06

Send a test email

Prove inbound forwarding, outbound identity and reply routing with an external inbox.

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07

Understand delivery statuses

Read accepted, forwarded, deferred, failed and held states without guessing.

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08

Recover a failed message

Inspect the response, fix the destination and retry when the dashboard permits.

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09

Manage seats and limits

Match domain, alias, storage, sending and team limits to the correct plan.

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Complete workflow library

Follow each task from start to verified result

01Verify domain→02Route MX→03Create aliases→04Connect SMTP→05Test both ways
01
Goal

Add and verify a domain

Prove that you control the domain before MailerZ accepts or sends mail for it.

  1. Open Domains → Add domain and enter only the root domain, without https:// or a mailbox name.
  2. Copy the unique TXT host and verification token into the authoritative DNS zone.
  3. Wait until a public DNS lookup returns the exact token, then choose Verify in MailerZ.

Expected resultThe domain shows Verified and unlocks alias, MX and sender-authentication setup.

ImportantDo not reuse a verification token from another domain or screenshot.

02
Goal

Configure MX records

Route new inbound messages to MailerZ without splitting delivery between providers.

  1. Inventory every existing MX record and confirm whether another mailbox service still depends on it.
  2. Create every MX record shown in MailerZ with the exact hostname and priority.
  3. At cutover, remove conflicting old MX records, then query the public MX set before testing.

Expected resultExternal mail servers discover MailerZ as the intended receiver for the domain.

ImportantMultiple unrelated MX providers can produce unpredictable delivery; priority is not a traffic-splitting feature.

03
Goal

Create aliases and destinations

Map each public address to the inbox or people who should receive it.

  1. Create a named alias such as support@yourdomain.com.
  2. Add one or more destination inboxes and complete destination verification when requested.
  3. Send an external test and confirm every intended destination receives exactly one copy.

Expected resultMessages to a named domain address follow a clear, auditable routing rule.

ImportantAvoid forwarding loops: a destination must not route back to the same alias.

04
Goal

Configure catch-all

Decide what happens when mail arrives for an address you never created.

  1. Start with Hold so mistyped and abusive recipients do not automatically reach an inbox.
  2. Review held-recipient patterns and create explicit aliases for legitimate recurring addresses.
  3. Enable Forward only on an eligible paid plan and only when the operational benefit exceeds the spam risk.

Expected resultUnknown-recipient behavior is intentional instead of accidental.

ImportantCatch-all forwarding increases spam exposure and can hide address typos.

05
Goal

Connect authenticated SMTP

Send from a verified custom-domain identity through MailerZ.

  1. Create or reveal a dedicated SMTP credential in the MailerZ dashboard.
  2. Copy the server, secure port, encryption mode, username and generated password into the client.
  3. Associate that outgoing server with the exact From identity and save.

Expected resultYour email client or application can authenticate and submit approved messages.

ImportantNever publish SMTP passwords, paste them into support forms or share one credential across unrelated systems.

06
Goal

Send a complete test

Prove receiving, forwarding, sending and reply routing—not only one direction.

  1. From an unrelated provider, send a uniquely titled message to the MailerZ alias.
  2. Confirm the destination inbox shows the original sender and the message appears in delivery history.
  3. Reply using the custom From identity, then inspect the received From address and reply back once more.

Expected resultOne traceable conversation completes the entire inbound and outbound loop.

ImportantTesting from the destination inbox to itself can hide routing or identity errors.

07
Goal

Understand delivery statuses

Translate dashboard states into the correct operational action.

  1. Accepted means MailerZ received responsibility for the message; it does not yet mean the destination accepted it.
  2. Forwarded or delivered means the next server returned success; inbox placement remains controlled by that provider.
  3. Deferred is temporary and may be retried; failed is terminal until the underlying cause changes; held requires review.

Expected resultSupport decisions follow evidence instead of assumptions.

ImportantAlways keep the full SMTP response and enhanced status code; the short label alone is not enough.

08
Goal

Recover a failed message

Fix the cause, then retry safely without creating duplicate delivery.

  1. Open the message event and record recipient, timestamp, attempts and the complete remote response.
  2. Correct the destination, DNS, policy or limit that caused the failure.
  3. Retry once from the dashboard when available, then confirm a new successful event before closing the issue.

Expected resultA recoverable message reaches the corrected destination with an audit trail.

ImportantDo not repeatedly retry a permanent 5xx response without changing the cause.

09
Goal

Manage seats and plan limits

Keep capacity ahead of real usage while avoiding unnecessary upgrades.

  1. Track domains, aliases, seats, stored days, monthly outgoing volume and peak send-as rate separately.
  2. Set internal alerts before the monthly or hourly ceiling becomes a production incident.
  3. Upgrade only when a measured limit is near; remove unused aliases, credentials and seats during reviews.

Expected resultThe workspace has enough headroom for normal peaks and clear ownership.

ImportantAn hourly send-as limit and monthly outgoing allowance apply at the same time; one does not replace the other.

Email apps

Send-as guides

Gmail Send as

Reply from your custom domain inside Gmail.

Outlook Send as

Configure a separate authenticated sending identity.

Apple Mail

Attach MailerZ SMTP to your existing inbox.

Thunderbird

Create an identity and choose its outgoing server.

WordPress SMTP

Send transactional site email through authenticated SMTP.

DNS providers

Record-by-record setup

Cloudflare

Field map, propagation notes and cutover warnings.

Godaddy

Field map, propagation notes and cutover warnings.

Namecheap

Field map, propagation notes and cutover warnings.

cPanel

Field map, propagation notes and cutover warnings.

Amazon Route 53

Field map, propagation notes and cutover warnings.

Something is not working?

Diagnose from the symptom you can see.

Translate SMTP codes, authentication failures, DNS problems and held-recipient states into the next useful action.

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Current plan limits

Free: 1 domain / 3 aliases / send-as, SMTP, and API disabled. Solo: 3 / 15 / 1,000 outgoing. Starter: 5 / 50 / 2,000. Business: 25 / 200 / 4,000. Agency: 100 / 500 / 8,000. Unlimited: uncapped domains and aliases / 100,000 outgoing. Hourly send limits also apply on paid plans.

See full pricing