What's the correct terminology for + email alias?
What's the correct terminology for + email alias?
It has a variety of names, including Sub-addressing, Detailed Addressing or SMTP Tags.
RFC 5233 - Sieve Email Filtering: Subaddress Extension:
Abstract
On email systems that allow for 'subaddressing' or 'detailed addressing' (e.g., "[email protected]"), it is sometimes desirable to make comparisons against these sub-parts of addresses. This document defines an extension to the Sieve Email Filtering Language that allows users to compare against the user and detail sub-parts of an address.
Sub-addressing
Some mail services support a tag appended to the local part, such that the modified address is an alias to the unmodified address. For example, the address
[email protected]denotes the same delivery address as[email protected]. The text of the tag may be used to apply filtering, or to create single-use addresses.Some IETF standards-track documents, such as RFC 5233, refer to this convention as sub-addressing. However, the automatic form validation of many web sites rejects
+as a valid character in the email address.Some service providers are inconsistent, and use address tags in their own outbound email, but disallow address tags for users.
Disposable email addresses of this form, using various separators between the base name and the tag, are supported by several email services, including Runbox (plus), Gmail (plus), Yahoo! Mail Plus (hyphen), Apple's iCloud (plus), Outlook.com (plus), FastMail (plus and Subdomain Addressing), and MMDF (equals).
Most installations of the qmail and Courier Mail Server products support the use of a hyphen
-as a separator within the local-part, such as[email protected]or[email protected]. This allows qmail through .qmail-default or .qmail-tag-sub-anything-else files to sort, filter, forward, or run an application based on the tagging system established.Postfix allows configuring an arbitrary separator from the legal character set. The separator info remains available on the email (address is not rewritten to remove it), and thus is useful in internal mail-routing, filtering, and forwarding via any of the mechanisms existing in Postfix.
Source Email address