This guide details the allowed and disallowed characters when creating an email address (up to 64 characters) in an Infomaniak Mail Service.

Preamble

• The allowed characters differ depending on whether they appear before or after the at sign @. For example, in username.mail@domain-name.xyz :
  • Before the at sign: the part username.mail corresponds to the username.
  • After the at sign: the part domain-name.xyz corresponds to the domain name.
• To learn about the possibilities offered at the domain name level (part after the at sign @), refer to this other guide.

Part before the at sign: username.mail

The RFC 5321 and RFC 5322 standards define the general syntax of email addresses. However, email providers — including Infomaniak — apply additional restrictions to ensure security, consistency, and compatibility with the majority of email software/clients.

For example, an address such as -@example.com is syntactically valid according to RFC 5322, but is not accepted when created on Infomaniak servers.

These additional rules notably allow:

• to avoid abuse (spam, malicious automation, etc.);
• to respect naming conventions (an identifier composed solely of - makes no sense);
• to ensure compatibility with email software/clients that poorly handle certain address formats.

In summary: RFC 5322 defines what is syntactically possible, but each server determines what is actually usable in practice.

Allowed characters before the at sign

The following characters can be used in the part before the at sign of an Infomaniak email address:

Forbidden characters before the at sign

The following characters (at sign, exclamation mark, hash, dollar, percent, caret, ampersand, asterisk, parenthesis, equal sign, bracket, chevron, comma, quotation marks, semicolon, question mark...) cannot be used to create an Infomaniak email address