FAQ for System Administrators

Why are my emails being delayed?

Delays in outgoing mail from Bluewin are mainly caused by our quarantine technology. This happens primarily when a message is detected as spam and there are no indications to the contrary that overrule this decision.

Inbound messages are throttled via "Deferrals" (SMTP Status 4XX). This can be for a variety of reasons, two of which are most important:

  • IP without history: This means new IPs have been used that have not been used or have not been used frequently for sending emails.
  • Poor IP reputation

Why do my emails end up in the spam folder?

Bluewin aims to provide Bluewin users with optimal protection against fraudulent and unwanted e-mails. Such e-mails will be automatically intercepted by the spam filter. The reasons for this include: unwanted content in the e-mail, poorly maintained distribution lists, or spam messages from users. If you send bulk e-mails or newsletters, follow [the recommendations for bulk e-mail senders and newsletters] so that your emails or newsletters are not marked as spam.

How can I make sure my emails aren't marked as spam?

To maximize the likelihood that your emails will not be rated as spam, we'll be happy to refer you to our [best practices] and M3AAWG recommendations.

How do I get on the wantlist at Bluewin?

Bluewin does not offer a wantlist. We follow the philosophy that every e-mail participant adheres to the legal framework and behaves responsibly towards the market participants.There are certification options through industry recognized companies and committees like Return Path or CSA. These precautions reduce the likelihood that your emails will be marked as spam.

Why is my server not allowed to connect to Bluewin systems?

Your server could be blocklisted. If this happens, a URL is sent in the Status Message, through which a delisting can be requested. The reason for the listing can be for one of many implementation specific factors and we cannot provide a generalized answer.

How does Bluewin rate the reputation of an email sender?

Various factors have an impact on the reputation of a broadcaster. The most important are:

  • Spam/Ham Ratio: The ratio of messages classified as spam to clean messages.
  • SMTP behavior: For example, repeatedly sending to non-existent addresses.

Why do my emails end up in the spam folder when my reputation is good?

Today, the sender's reputation has an impact on the permitted throughput of messages. However, the placement in the Inbox or whether something is declared spam is conditional on message content.

What is the maximum message size that Bluewin Mail accepts?

Bluewin limits message size to 15MB.