DKIM 2048 Overview and Updates

DKIM (DomainKeys Identified Mail) is an important part of email authentication. It helps receiving mail servers verify that a message hasn’t been altered and that it genuinely comes from the sender’s domain.

Recently, more organizations have begun moving to 2048-bit DKIM keys for stronger security. Here’s what that means and the current status of DKIM support in Postmark.

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💥 What Is DKIM 2048?

DKIM works by attaching a digital signature to your outgoing emails. That signature is verified using a cryptographic key stored in your domain’s DNS record.

A 2048-bit DKIM key is simply a longer encryption key than the standard 1024-bit key. The longer the key, the harder it is for attackers to break or forge.

In short:

• 1024-bit DKIM = Standard and widely used today

• 2048-bit DKIM = Stronger, modern encryption that offers more protection against spoofing and forgery

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⚠️ DKIM 2048 Support in Postmark

At this time, Postmark’s DKIM implementation uses 1024-bit keys.
We do not currently support 2048-bit DKIM keys.

There is an open feature request for 2048-bit key support, but there’s no confirmed timeline for when this feature will be available.

We understand that stronger authentication is a priority for many senders, and we’ll share updates if this feature becomes available in the future.