Email Sending Limits for Spamhaus-Listed Domains

Why your emails are being limited?

If your mail is bouncing with a message like this, your domain is on the Spamhaus Domain Block List (DBL), and Titan has temporarily reduced how much email it will accept from you:
 

550 5.4.6 [domain=yourdomain.com] is listed on the Spamhaus DBL and is temporarily rate-limited. Please delist the domain and retry later.

Spamhaus is an independent anti-abuse organisation, and its block lists are used by most major mailbox providers. By the time your domain appears on the DBL, providers like Gmail, Outlook and Yahoo are already treating your mail as suspicious. Much of it will land in spam or be rejected outright, whatever Titan does.

Titan lowers your sending limit while you're listed for the same reason we watch bounce rates: to stop a compromised or misused domain from sending thousands more messages and doing lasting damage to your sender reputation. The limit is temporary, and it lifts on its own once you're delisted.

The sending limit while your domain is listed

While your domain is on the DBL, Titan caps outgoing email from it to:

This replaces your normal allowance for as long as the listing stands. For comparison, a domain normally gets 1000 emails/hour and 2000 emails/day, and a paid domain gets the combined sending limit of all its active mailboxes, so the reduction is substantial, and deliberate. You can refer to the following article for a better understanding of Titan’s standard email sending limits: Titan Email Sending and Receiving Limits

 

Check your listing and get it removed

1. Go to the Spamhaus lookup tool at check.spamhaus.org.
2. Enter your domain name (for example yourdomain.com, not a full email address) and run the check.
3. If your domain is listed, the result names the DBL and shows a return code.

That return code tells you why you were listed, which decides how you fix it.

The codes beginning 127.0.1.10 mean Spamhaus believes your domain is genuine but compromised. Someone else is abusing it. That is the most common case and it usually points to a hacked mailbox or an insecure form on your website.

Fix the cause first. Spamhaus re-lists a domain that is still compromised, and removal requests made without a fix are refused.

1. Change the password on every mailbox on the domain, and turn on two-factor authentication.
2. Check sent folders for mail you didn't send, and look for forwarding rules or filters you didn't create.
3. If the domain hosts a website, patch it. Check contact forms, plugins, open redirects and any uploaded files.
4. Remove any phishing or malware content the listing refers to.
5. Stop sending to any purchased or scraped list, and delete those addresses.

Then request removal.

1. Go to check.spamhaus.org and look up your domain.
2. Open the listing and follow its removal link to the Spamhaus Blocklist Removal Center.
3. Say what the cause was and what you changed. A specific, honest answer is processed far faster than a blank request.

Many DBL listings also expire on their own once the abuse stops, so if you have genuinely fixed the cause, you may find the listing clears without a request.

After you're delisted

Your normal sending limit returns automatically. There is nothing to switch back on at Titan's end, and you don't need to contact us.

Allow a little time, though:

• Titan works from a regularly refreshed copy of the block list rather than querying Spamhaus on every email, so there is a short delay between Spamhaus removing you and the reduced limit lifting.
• Any hourly or daily counter you already filled while listed still has to run out. If you had already sent 50 that day, the daily counter clears 24 hours after it started, not the moment you are delisted.
• Other mailbox providers keep their own reputation history. Coming off the DBL stops the immediate blocking, but rebuilding trust with Gmail or Outlook takes consistent, clean sending over days or weeks.

Avoid being listed again

• Use a strong, unique password on every mailbox, and turn on two-factor authentication. A compromised mailbox is the single most common route onto the DBL.
• Set up SPF, DKIM and DMARC for your domain. See Email Authentication Measures.
• Build your recipient list organically. Never buy or import a public list. See Email Bounce Back.
• Keep any website on the domain patched, and lock down contact forms and redirects.
• Watch your bounce rate. A sudden spike is often the first visible sign that a mailbox has been compromised.
• Keep your domain's spam rate below 0.30%.
• Check your domain at check.spamhaus.org occasionally, rather than waiting for mail to start failing.

Still need help

Contact Titan support with:

• Your domain name.
• The full bounce message, including the 550 5.4.6 line.
• A screenshot of your check.spamhaus.org result.
• What you have already changed, and when?

If you’ve already requested removal from Spamhaus, let us know when. We can verify what Titan is seeing and confirm whether your normal sending limits are restored once the listing is cleared. Please note that the removal itself must be handled by Spamhaus.