How to Connect MailWizz to Your Own SMTP Server - Step by Step

Connecting MailWizz to your own SMTP server takes about 30 minutes: create a delivery server entry (Backend → Servers → Delivery servers) pointing at your server on port 587 with TLS, set hourly quotas that match your IP's warm-up stage, configure a bounce server so dead addresses get removed, and verify SPF/DKIM/DMARC alignment before the first campaign. The combination of a one-time MailWizz license (~$100) and a dedicated SMTP server is one of the cheapest legitimate bulk-email stacks running, often under $150/month total at volumes where ESPs charge $1,000+.

I've deployed this stack for a dozen clients. The exact setup, including the bounce handling and quota details most tutorials skip.

What you need before starting

If your SMTP server runs Postal, you get webhook-based bounce handling instead of IMAP polling, cleaner, covered below.

Step 1: Create the delivery server

In the MailWizz backend: Servers → Delivery servers → Create new → SMTP.

Fill in:

1. Hostname: your SMTP server, e.g. mail.yourdomain.com
2. Port: 587 with TLS (or 465 for implicit SSL, match what your server offers)
3. Protocol: TLS
4. Username / password: your SMTP credentials
5. From email: an address on the domain whose SPF/DKIM you've published, alignment matters more than the address itself
6. Hourly quota / daily quota: see step 2; do not leave these unlimited

Click Validate server. MailWizz sends a confirmation email to the address you specify, click the link in it to activate the server. If validation fails, test the same credentials with a manual SMTP session (swaks or openssl s_client) before debugging MailWizz.

Step 2: Set quotas to match your warm-up

This is the step that separates working deployments from blacklisted ones. A fresh IP cannot send 50K emails on day one. Gmail and Microsoft will defer, then junk, then block.

Set the delivery server's hourly quota to roughly your current warm-up day's allowance divided by sending hours:

Raise the quota every few days only if bounce and deferral rates stay clean. A managed SMTP provider will give you (or enforce) this schedule; if you're self-managing, the discipline is on you.

Step 3: Configure the bounce server

Without bounce processing, every campaign re-mails the addresses that bounced last time, and your hard-bounce rate compounds until receivers block you.

Classic IMAP route: Backend → Servers → Bounce servers → Create new. Point it at the IMAP mailbox receiving bounces (the Return-Path mailbox), e.g. [email protected], with its IMAP host, port 993/SSL, and credentials. MailWizz polls it via cron, parses bounce codes, and marks subscribers as bounced automatically.

Postal/webhook route: if your sending server is Postal-based, skip IMAP and use the delivery-server type for it or a webhook integration, bounces arrive in real time instead of on a polling delay. (Which server software to run is its own decision, see Postal vs Postfix.)

Either way, also create a feedback loop server if your provider exposes complaint feeds, so spam-button presses unsubscribe people automatically.

Step 4: Verify authentication before the first campaign

Send a test to a mail-tester service and to your own Gmail/Outlook accounts. Check:

• SPF: pass, and the envelope domain matches your sending domain.
• DKIM: pass, with d= equal to your sending domain (alignment), not the server's default hostname.
• DMARC: at least p=none published, with alignment passing.
• rDNS: the sending IP resolves to a hostname that resolves back to the IP.

A surprising number of "MailWizz deliverability problems" are just a DKIM signature on the wrong domain. Fix infrastructure first; templates and copy are second-order. The complete infrastructure checklist is in how to set up an SMTP server for bulk email.

Step 5: Cron jobs and a test campaign

Confirm the MailWizz cron jobs are installed (the install screen lists them; send-campaigns runs every minute, bounce-handler every 10-20 minutes). Then run a small test campaign, 50-100 subscribers across Gmail, Outlook, and Yahoo, and read the delivery server logs.

What to look for: acceptance (250 responses), any 4xx deferrals (slow down), any 5xx rejections (stop and diagnose). Only scale up when a small send is clean.

Common failure modes

How BulkEmailSetup helps

BulkEmailSetup provides MailWizz-ready dedicated SMTP servers, credentials handed over with SPF, DKIM, DMARC, and rDNS already configured, plus a managed warm-up schedule so your quotas have numbers behind them. Pair a one-time MailWizz license with a flat-fee server and the whole stack costs less than most ESPs' starter tiers; see pricing.

Frequently asked questions