Why Validation Matters
In Mapp Engage, the email address is the primary identifier for every contact. To ensure data quality and protect your sender reputation, the system checks each address when you import or add contacts. Invalid addresses can harm deliverability, as ISPs automatically block messages sent to them, which in turn can damage your standing as a marketer.
That’s why Mapp Engage applies a set of validation rules before an email address can be stored in the system.
Validation Rules
Mapp Engage verifies that each email address meets the following criteria:
Valid Characters
The local part (before the “@”) may include letters, numbers, and specific special characters:
! # $ % & ' * + / = ? ^ _ { | } ~`.The domain part (after the “@”) may include letters, numbers, and certain special characters. It also supports letters with diacritical marks and the sharp S character (ß). These are automatically converted to Punycode for storage.
Note: diacritical marks and the ß character are not allowed in the local part.
Dot Usage
Dots are allowed in the local part but cannot appear at the beginning or end.
Consecutive dots (e.g.,
..) are invalid.
Length Restrictions
The domain part cannot exceed 63 characters.
The entire email address cannot exceed 129 characters.
Behind the scenes, Mapp Engage uses a regular expression to enforce these rules consistently.
Examples
Valid Addresses
jane.sample@example.com→ Dots are allowed in the prefix.janesample@example.com→ A dot in the prefix is optional.jane.sample@exämple.com→ Letters with diacritical marks are allowed in the domain.jane.sample@exampleß.com→ The sharp S (ß) is allowed in the domain.
Invalid Addresses
jöe.sample@example.com→ Diacritical marks are not allowed in the prefix.joe.ßchmidt@example.com→ The sharp S (ß) is not allowed in the prefix.joe.sample.@example.com→ The prefix cannot end with a dot..joe.sample@example.com→ The prefix cannot begin with a dot.joe..sample@example.com→ The prefix cannot contain consecutive dots.