Mail Server Tools

Test your SMTP connection, send a test email, verify SPF/DMARC records, and check whether your IP is blacklisted.

Enter your mail relay, sending server or your own SMTP credentials. Connection and authentication are tested step by step.

A real test email is sent through the SMTP server you provide.

Enter your mail server IP (or domain); it is queried against known blacklists including Spamhaus.

What Are Mail Server Tools and What Do They Do?

IzHost Mail Server Tools is a free toolkit that lets system administrators, developers and businesses test the health of their email infrastructure in one place. It tests your SMTP server connection and authentication step by step, verifies delivery by sending a real test email, analyses your domain's SPF/DMARC/MX records, and checks whether your server IP is on known blacklists (Spamhaus, SpamCop, Barracuda and more).

Are your emails landing in spam, failing to send, or are you wondering "why won't my mail go through"? These tools diagnose the most common causes of email deliverability problems — misconfigured SMTP, missing SPF/DMARC records, blacklisted IP addresses — in seconds. No installation required; everything runs from your browser.

Tools and Use Cases

SMTP Connection & Authentication Test

Enter your server, port (25/465/587), username, password and encryption (Plain, STARTTLS or SSL/TLS); we test each step — connection, EHLO, STARTTLS and AUTH — separately. Instantly see whether your mail relay, sending server or your own SMTP account works, and pinpoint wrong credentials or port/encryption mismatches.

Send a Real Test Email

Using the SMTP credentials you provide, we send a real test email to the recipient you choose. Verify end-to-end whether the email reaches its destination, lands in spam, and that your server can actually send mail.

SPF, DMARC & MX Record Verification

Enter your domain; we read and verify the SPF record (and its policy: hard fail, soft fail, neutral), the DMARC record (policy p=none/quarantine/reject) and the MX records. Missing or misconfigured email authentication records are a leading reason emails get rejected or flagged as spam.

Blacklist (DNSBL) & Spamhaus Check

Queries your mail server IP or domain against well-known DNS blacklists (DNSBL) including Spamhaus ZEN, SpamCop, Barracuda, SORBS, CBL, PSBL and UCEPROTECT. If your IP is blacklisted, most providers block your email — this check helps you catch the problem early.

Frequently Asked Questions

Why does my SMTP test fail?
The most common causes: wrong port/encryption combination (STARTTLS for 587, SSL/TLS for 465), incorrect username or password, the server refusing the connection, or a firewall block. The test steps (Connection, EHLO, STARTTLS, AUTH) show exactly where it failed.
Why are SPF and DMARC important?
SPF declares which servers may send mail on behalf of your domain; DMARC tells receivers what to do when SPF/DKIM fail. Correctly configured SPF and DMARC records keep your emails out of spam at providers like Gmail and Outlook and prevent your domain from being spoofed.
My IP is blacklisted — what should I do?
First find out why you were listed (usually spam sending, an infected device, or an open relay). After fixing the issue, use the delisting form on the relevant blacklist's site (e.g. Spamhaus). If you are an IzHost customer, our support team can help with the process.
The test email did not arrive — why?
If the email was sent but did not arrive, check the recipient's spam/junk folder, verify your SPF/DMARC records, and check whether your sending IP is blacklisted. Using these three tools together helps you narrow down the source of the delivery problem.
Are these tools free, and is my data safe?
Yes, all tools are free. The SMTP credentials you enter are used only for the test request and are not stored. For security, only standard mail ports and public IP addresses are allowed.
Which encryption option should I use?
STARTTLS on port 587 is generally recommended. If you use port 465, choose SSL/TLS (implicit). Port 25 is mostly for server-to-server transfer (plain or STARTTLS). If unsure, try 587 + STARTTLS first.