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Alias vs Plus-Address Explainer

you+tag@gmail.com goes to the same inbox as you@gmail.com — but the CRM, the analytics tool, and the deduper all think they're different.

Examples — same person, three CRM rows
Stored asActually delivers toProvider strips it?
sam@gmail.comsam@gmail.com
s.a.m@gmail.comsam@gmail.comGmail ignores dots
sam+vendor@gmail.comsam@gmail.comGmail strips +tag for routing, keeps it in headers
sam@googlemail.comsam@gmail.comgooglemail.com is a Gmail alias domain
sam@yahoo.com vs sam+x@yahoo.comDifferent inboxesYahoo does NOT support plus-addressing

Before deduping a list, normalize: lowercase, strip dots for gmail.com/googlemail.com, strip +tag for providers that support it.

What it does

Worked examples showing how the same person can appear three times in your CRM as alias, plus-address, and primary; how to normalize.

When to use

Before deduplicating a contact list. Before building any signup form on a free-email-domain audience.

FAQ

Which providers support plus-addresses?+

Gmail (yes), Outlook.com (yes since 2020), Apple iCloud (yes), Fastmail (yes), Yahoo (no), most corporate Exchange (depends on admin config).

You know the rule. See where you sit against it.

Reference pages tell you the benchmark. Outsolvi tells you whether your team is above or below it — per-rep, per-deal, per-week — and which behavior changes move the number. From $7/user/mo yearly.

See your number
Nate SummersCo-Founder, Outsolvi

Nate built Outsolvi after watching every email-tracking tool he had ever used lie to him about opens. Outsolvi runs Tier 1 to 5 confidence scoring on every open, native in Outlook and Gmail, so the number on the dashboard is one a rep can actually act on.

Last reviewed May 25, 2026Editorially independent

We update these pages when the underlying mechanics change — new mailbox-provider rules, new tracker behavior, new measurement gaps. The dates above are real revisions, not auto-touches.