TopicIT Networking →
⌚ About 2 min read
Identify servers that receive emails from a domain.
Avant de commencer : adaptez toujours les commandes et manipulations à votre environnement. Sur un système de production, prévoyez une backup ou un retour arrière lorsque l’action peut modifier la configuration.
Étapes à suivre
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1
Open a terminal.
Use Windows Terminal or Power Shell.
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2
Ask type MX
Run Resolve-Dns Name domain.fr -Type MX.
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3
Read priorities
A lower preference value is generally a priority.
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4
Solve Targets
Then check that the names of the MX servers are properly resolved.
Commands utiles
Resolve-Dns Name example.fr -Type MX
À retenir
- Editing MX can interrupt the reception of,email.
- MX records must point to of host names, not directly to IP addresses.
MX: priority, target and resolution must be consistent
Technical checkpoints
- The lowest numeric value has the highest priority; multiple MX records at the same priority can provide load sharing or redundancy.
- An MX target must be a resolvable hostname; it must not be an IP address.
- An MX target must have coherent A/AAAA records and accept SMTP on the expected port from the Internet.
Example
Compare MX order then resolve each target separately.
10 mx1.example.com.
20 mx2.example.com.Topic-specific pitfalls
- Do not invert priorities: 10 is preferred over 20.
- An old MX still published can continue receiving part of the traffic if its priority remains valid.
How to validate
- Each MX target resolves and answers SMTP as designed.
- Old MX targets and transition TTLs are removed after the migration window.