Local Address Extension Reference

Local address extension (RFC 5233 subaddressing) delivers mail to extended addresses at the same mailbox without extra configuration. A configurable delimiter plus a tag is appended to the local part; all such mail is delivered to the base mailbox.

Configuration

Example with default delimiter -:

user1-friends@example.com
user1-newsletter@example.com

Example with RECIPIENT_DELIMITER=+:

user1+friends@example.com
user1+newsletter@example.com

Sieve

Extended addresses can be matched in Sieve. Example for user1-newsletter@example.com:

if address :matches :localpart "to" "user1-newsletter*" {
    fileinto "Newsletters";
}