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Outbound Emails to Recipients with German Umlauts (ä, ö, ü) Bounce with "Unable to Get MX Info"

Contents

Overview

Outbound emails to recipients whose email addresses contain German umlauts (ä, ö, ü) fail to deliver and bounce. The technical bounce reason appears similar to "unable to get mx info…", which means the recipient's domain could not be found.

This is not a Kayako defect. The root cause is a recipient-data problem: the affected addresses were stored with the umlaut written out in the "ae/oe/ue" form (for example, office@gynaekologie-pempelfort.at instead of office@gynäkologie-pempelfort.at). The "ae" spelling produces a different domain name that is usually not registered and does not exist in DNS, so no mail server can be found and the message bounces.

The resolution is to store the domain's punycode (ASCII-compatible) form, which always begins with xn-- and points to the exact same mail servers as the umlaut version. Kayako's email fields accept the xn-- form but do not accept the literal ä/ö/ü characters. Note that many addresses can bounce for this same underlying reason — the recipient domain does not exist (often simple domain typos).

Solution

Confirm the Symptom

Messages sent to recipients with German umlauts (ä, ö, ü) in their email address fail to deliver and bounce. To view the technical reason, open the failing conversation and hover over the X (bounce) symbol on the message. If you see a reason similar to "unable to get mx info…", it means the recipient's domain could not be found.

Why This Happens

The failure is caused by how the recipient address is stored, not by an inability of Kayako to send to these recipients.

Internationalized domains that contain umlauts (for example, gynäkologie-pempelfort.at) are frequently written with the umlaut "spelled out" as ae/oe/ue (for example, gynaekologie-pempelfort.at). These are two different domain names:

  • gynäkologie-pempelfort.at — the real, registered domain with working mail servers.
  • gynaekologie-pempelfort.at — the "ae" spelling — a different domain that is usually not registered and does not exist in DNS.

When a message is sent to the "ae" address, the delivery system looks up the mail servers (MX records) for the non-existent domain, finds none, and bounces. This is why it appears that umlaut addresses fail — whenever an umlaut domain is written out with ae/oe/ue, the result is a different domain that typically isn't registered.

The Fix — Use the Domain's Punycode Form

Internationalized domains have a standard ASCII-compatible representation called punycode, which always begins with xn--. The punycode form points to the exact same mail servers as the umlaut version and delivers identically. Kayako's email fields accept the xn-- form, but do not accept the literal ä/ö/ü characters — so punycode is the reliable way to store these contacts.

Example conversion:

  • Real recipient: office@gynäkologie-pempelfort.at
  • Enter in Kayako (punycode): office@xn--gynkologie-pempelfort-71b.at

Additional worked examples:

Real recipient (umlaut) Enter in Kayako (punycode)
ordination@frauenärztin-gösting.at ordination@xn--frauenrztin-gsting-qtb18a.at
praxis@kaut-homöopathie.at praxis@xn--kaut-homopathie-gtb.at
info@orthopädie-haiden.at info@xn--orthopdie-haiden-0nb.at
info@wirbelsäule-aigelsreiter.at info@xn--wirbelsule-aigelsreiter-17b.at

Tip: You can obtain the punycode form of any umlaut domain using a standard IDN/punycode converter. Convert only the domain portion (right of the @), then combine the result with the original local part (the text before the @).

How to Correct an Address in Kayako

  1. Open the contact's profile.
  2. Add the corrected (punycode) email as a new identity.
  3. Mark the new identity as verified.
  4. Set it as the primary email.
  5. Remove the old (incorrect) address.

For the detailed steps to add, verify, and update identities on a contact, see Updating the Email Address, Phone Number, or X Handle of a User Account. For background on how bounces are surfaced and what other causes to check, see Messages are Bounced Instead of Being Delivered.

Verify the Fix

  • Send a test message to the corrected contact and confirm it no longer bounces.
  • Confirm the corrected address is set as primary and the old address has been removed.

Important Scope Notes

  • This applies to umlauts in the domain (the part to the right of the @).
  • If a contact has an umlaut in the local part (to the left of the @, for example büro@…), the punycode approach does not apply and a different handling is required.
  • The same bounce behavior — "domain could not be found" — can affect any address whose recipient domain does not exist, most commonly due to a domain typo (an extra or missing letter). For any address flagged "domain not found," verify the correct spelling directly with the contact and update it in Kayako.

Note: No product defect is involved, and no external team can create MX records for a recipient domain that does not exist. Correcting the stored address resolves the bounce.

Frequently Asked Questions

1. How do I know this is the issue affecting my failed emails?
Check the bounce/technical reason on the failing conversation by hovering over the X symbol on the message. If you see a reason similar to "unable to get mx info…" it means the recipient's domain could not be found. If the affected addresses contain German umlauts written out as ae/oe/ue (for example, gynaekologie-… for gynäkologie-…), you are almost certainly hitting this issue — the "ae" domain is a different, unregistered domain.
2. Why can't I just type the umlaut characters (ä, ö, ü) directly into Kayako?
Kayako's email fields do not accept literal ä/ö/ü characters. Use the domain's punycode form instead — it always begins with xn--, points to the exact same mail servers, and delivers identically to the umlaut version.
3. How do I get the punycode form of an umlaut domain?
Convert only the domain portion (right of the @) using any standard IDN/punycode converter. The result begins with xn--. Then combine it with the original local part. For example, office@gynäkologie-pempelfort.at becomes office@xn--gynkologie-pempelfort-71b.at.
4. What if the umlaut is before the @ symbol (in the local part), like büro@example.at?
The punycode fix applies only to umlauts in the domain (right of the @). Umlauts in the local part require a different approach — contact Support with the specific address for guidance.
5. Some of my failing addresses don't have umlauts at all. Why are they bouncing?
The same underlying cause — a recipient domain that does not exist — can result from simple domain typos (an extra or missing letter). For any address bouncing with a "domain not found"/"unable to get mx info" reason, verify the correct spelling directly with the contact and update it in Kayako.
6. Is this a Kayako bug that needs to be fixed by the product team?
No. This is a recipient-address data issue — the stored address points to a domain that doesn't exist, so there is no mail server to deliver to. No product defect is involved, and no external team can create MX records for a non-existent recipient domain. Correcting the stored address (using punycode for umlaut domains, or fixing the typo) resolves it.
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