We keep a list of blocked senders and recipients on each server. If you think you've been blocked unfairly, we're happy to talk it through.

Blocked Sending Address

Your address was blocked from sending mail. Some common reasons:

You’re sending way too many cron job emails

This one’s mostly about v2board. Here’s the deal:

You’re firing off one email every minute from a bad address to a bad recipient, and it’s always the same: noise. It floods our queue, triggers alerts, and turns us into janitors writing block rules just to stop it. This happens constantly and it's exhausting.

If you’re relaying your whole Linux server through us, make sure it’s only sending real emails that a human might want to read.

Too many bounces

You’ve sent a lot of email to addresses that don’t exist. This usually means:

• You're sending spam
• You're using a mailing list without confirmed opt-ins
• You made a mistake that could hurt your domain’s reputation

Your contact form is being abused

Usually WordPress. Spammers are using your form to blast junk to services like Gmail or Yahoo. We want a good relationship with them, and this makes it harder.

You’re dodging the rate limit

Sending the same campaign from multiple addresses like sender1, sender2, etc.? That’s not okay. 300 emails per hour is the limit.

You sent marketing emails

We don’t allow marketing emails. If we only blocked your sender address, it means we think you didn’t know better and can fix it. Otherwise, we’d have shut down the whole account.

SPF issues

You didn’t update your domain’s SPF record to include us. As a result, your emails are getting rejected. Fix your SPF, then open a support ticket.

You’re spoofing

You sent emails from a domain you don’t own. That’s an automatic block.

You used an invalid sender address

Things like root@localhost don’t work — we can’t bounce emails back to those, and they clutter the mail queue. So we block them.

You're violating policy (badly)

It’s not just a little over the line. It’s way over. Enough said.

Blocked Recipient Address

Sometimes it’s not about the sender — it’s about who you’re sending to.

You tried to send email-to-SMS

We don’t allow this. It’s a long story, but trust us — there are good reasons.

Someone didn’t want your emails

You kept sending anyway. Now it’s blocked, and you’ll get a proper error message next time.

Spammy cron job junk to third parties

No one is reading those 600 notifications you’re sending to Gmail. You're just wasting resources and eating into your rate limits.

Repeatedly sending to dead addresses

If it doesn’t exist, stop trying. We're blocking these to avoid wasting cycles bouncing them.

Sending to domains with no MX records

These can’t receive email, so we block them. Keeps our IPs clean and our systems efficient.

You’re forcing quota errors

If you’re filling up someone’s inbox on purpose so everything bounces — we’re not playing that game.

The recipient’s server is broken

Sometimes their system thinks we’re blacklisted when we’re not. That’s their problem, not ours. We won’t waste resources fixing it on their behalf.

Want to Dispute a Block?

Open a ticket with us.