Mailbox Delivery Block - Posmay Media

Mailbox Delivery Block

Mailbox Delivery Block

Updated: 22 Oct 2018 — We'll keep this page updated.

Mail Block Issue Resolved

We can confirm that the mail block issue has been resolved. If you experience any email delivery issues, please email and attach the error message.


Some clients are experiencing email deliverability issues when sending emails from mailboxes that are hosted with Posmay Media. We understand how frustrating this is and appreciate your patience and understanding.

Error Message Example

Here is an example of the error message that you will receive if and when your email is blocked.


These bounced emails are only being blocked by a limited amount of email providers that are applying the spam filter services of UCEProtect, Backscatter, and/or LashBack.

Unfortunately, we cannot provide a complete list of these email providers, but from our recent investigations it seems like MWEB and iAfrica (South African Internet Providers) are two examples of email providers applying these blacklist rules.

In other words any emails that you send to a mailbox that is being hosted by MWEB or iAfrica (or any other email provider that applies these blacklist rules) will block emails coming from your mailboxes.

Our mail admin team is doing everything they can to remove any blocks as soon as they occur.

Although the spam run initially responsible for the block (blacklisting) was mitigated fairly quickly, some blacklist providers (Mostly European providers such as UCEProtect, Backscatter, and LashBack), provide a paid “express" delisting, while imposing an unreasonably long wait for delisting (In the case of UCEProtect, they auto-delist after a month). As this amounts to extortion, it is our policy not to utilize paid delisting services as they provide no added benefit to customers, encourage "bad behaviour".

Advice & Solution

1. The best advice we can provide in this situation would be to contact the recipient, and request that they contact their mail system administrator in order to request that they whitelist your domain. 

2. You can contact the recipients that are blocking your mails via some other channel and wait for the blocks to be removed.

3. If this is an ongoing issue for emails that you need to send to specific email recipients that are blocking your emails, then you can consider moving your mailboxes to a different email host. We recommend considering the following options.

  • FastMail — $3 per user per month
  • Zoho — $3 per user per month
  • GSuite — $5 per user per month
  • Gmail — Free, but ad supported

If you switch your domain's mailboxes to another email host, then we'll need to update your domain settings. We can help you configure these settings.

Need Additional Support?

Contact us if you have any additional questions.