Domain Validation in CloudMail¶
The CloudMail service accepts only emails for validated domains, based on the MX record as described in the handover protocol or this knowledge base article.
How often does the validation check run?¶
Validation takes place approximately 4 times per hour.
How to ensure domain is validated before changing MX records?¶
First of all, changing MX records to CloudMail, when the domain is not yet validated, will not cause any problems. Emails, that other servers would try to deliver to CloudMail, would be greylisted. So, the email is temporarily rejected and the mail server must try to deliver it again. Therefore, the mail will not be lost or returned to the sender, its delivery will be just temporarily delayed.
The domain can be validated in advance by adding another MX record (pointing to CloudMail) to the existing MX records. Set the priority of this record lower than for your production mail servers. Pay attention to how the priority of MX records is interpreted - if you currently have 2 MX records, one with priority 10 (primary), the other with priority 20 (secondary), then set the MX record for CloudMail to at least 21. After validating the domain, remove the original MX records and leave only the records pointing to CloudMail. We recommend that you do not complicate the whole procedure and simply change the MX records to CloudMail during off-peak hours. This simplifies the whole process and the delayed mail should not be a problem.