The Uniserv service Email Validation checks that an email address is valid and messages can be delivered
correctly to that address.
The actual verification of the email address considers the following three aspects: syntax check, domain check and mailbox check.
In addition to the validation result, further information about the email address may be relevant. For example, it may
be interesting to know if it’s a disposable address. How to request further information can be found on page
The actual verification of the email address considers the following three aspects: syntax check, domain check, mailbox check.
The syntax check is a check for irregular characters and character strings according to various RFC standards. These prohibit e.g.:
Two consecutive dots
Certain special characters
Dot as the last character before the @
This is only a small selection of the exceptions, but it includes the syntactic errors which most frequently occur in email addresses.
The domain check describes the process of validating the part of an email address after the @ character. A query is sent to the DNS Server, and both the existence of the domain and the existence of a mail server are tested, i.e. whether the domain is able to receive emails at all. If the check of both test criteria is successful, the domain check is regarded as concluded.
The mailbox check verifies that the local element of an email address exists on the mail server. It is thereby verified that an email can be sent to the stated address without errors.