Email deliverability

Email headers will tell the full transit story of a particular email. This can often help diagnose possible delivery or alignment issues.

Details of why having MX records for multiple mail providers is not a supported configuration.

Looking to whitelist an email address you frequently receive mail from?

Details about the possibilities when it comes to using ImprovMX for bulk mailing or mailing lists.

ImprovMX employs a basic layer of spam protection on the system level using the industry standard Spam Assassin software. We are continually monitoring and adjusting the filtering criteria in order to provide the optimum experience for our users.The

Using Regex (Regular Expressions) to Supercharge your Email Forwarding

A brief introduction to our favourite kind of DNS records: the MX record.

ImprovMX uses Spam Assassin to help protect users against spam mail.

How many emails can you receive, forward or send using ImprovMX forwarding and SMTP capabilities.

It is possible to redirect a forwarding alias to more than one email address. Just separate them with a comma, and you're all set!

This article will address some common problems with outgoing mail landing in spam.

Frequently asked questions and issues regarding Gmail SMTP and the "send mail as..." feature with your custom domain.

Here is a list of error codes returned by our server when you try to send an email. This should help you better understand why an email was refused and if it’s something on our end or yours.5.9.0 – Loop detected: Email is sent and forwarded from/to i

We've recently moved away from requiring premium users using different MX records for simplicity and ease of use.

We forward emails with attachments for up to 10MB per email (including message and attached files) and up to 50MB for our premium members.We refuse some attachments for security reasons. The list is basically the same as the other main email provider

The Sender Policy Framework is commonly used for service that sends emails. With email forwarding, we need you to add us to your SPF.

We're using Spamhaus to detect spam emails and protect our email deliverability. Learn how to troubleshoot issues you might having.

You may have received feedback from someone trying to send you an email which was refused with a message related to DKIM signature.

About ImprovMX's implementation of ARC

Your server can connect to ImprovMX servers by encrypting the connection using TLS or STARTTLS.In order to be compatible, we support a broad set of ciphers and protocols, which range from SSLv3 to TLSv1.3.Here's the full list: SSLv3 ADH-AES256-SHA

Occasionally, you may encounter a "Line too long" error on received emails. Learn what it means and how we handle the error.

Guidance on the "Too much mail data" error encountered in ImprovMX.