Regexes in Aliases

What Are Regex Aliases?

Use regular expressions to match patterns in email aliases and forward them dynamically. This handles multiple similar addresses with a single rule.

Using Substitutions

You can use $1, $2, etc. to insert values matched by regex groups (parentheses) into the destination email address.

• $1 = first matched group
• $2 = second group, and so on

Example: An alias pattern (.*)@yourdomain.com forwarding to $1+john@gmail.com would forward john.doe@yourdomain.com to john.doe+john@gmail.com.

Note: The alias field must not exceed 150 characters.

Order of Importance When Matching an Email

Evaluation follows this priority:

1. The exact match
2. The "Plus sign" match
3. The Regex match
4. The Wildcard or catch-all match *

Only the highest priority rule activates regardless of multiple matches.

The "Plus Sign" Match

When an email contains a plus sign (e.g., contact+label@piedpiper.com), ImprovMX:

• Matches it to the base alias
• Forwards to the configured destination
• Adds the same +label to Gmail addresses

Example: Sending to contact+newsletter@piedpiper.com with a base contact alias forwarding to Gmail results in delivery to richardhendricks+newsletter@gmail.com.

Note: Only works for specific email providers, not G-Suite domains.

Accepted Domains for Regex Plus Sign Forwarding

gmail.com, hey.com, protonmail.com, icloud.com, fastmail.com, outlook.com, runbox.com, yandex.com, yandex.ru, mailfence.com