Clean Autofill supports two email generation modes. Which modes are available depends on your email provider and domain setup.
Format: yourname+website.com@provider.com
Uses sub-addressing (based on the concept described in RFC 5233, which defines Sieve filtering for subaddressed emails) to append the visited site's domain as a tag. The + separator convention is provider-specific — requires an email provider that supports it. No setup needed; it works automatically.
Format: website.com@yourdomain.com
Uses the visited site's domain as the entire local part. Requires you to own a domain with catch-all email routing configured so that any address @yourdomain.com is delivered to your mailbox.
| Provider | Domains | Support page | Notes |
|---|---|---|---|
| Gmail | gmail.com, googlemail.com |
Use Gmail aliases | googlemail.com is treated as equivalent to gmail.com. No setup needed. |
| Google Workspace | Custom domains | Create a variation of your address | Works on any domain hosted on Google Workspace. |
| Microsoft 365 / Exchange Online | Custom domains | Plus Addressing in Exchange Online | Receive-only; no alias must be created first. |
| Outlook.com / Hotmail / Live | outlook.com, hotmail.com, live.com, msn.com |
Add or remove an email alias | Microsoft's clearest plus-addressing docs are for Exchange Online. Consumer Outlook.com commonly works with +tag but Microsoft's official consumer alias page does not explicitly document it. |
| Proton Mail | protonmail.com, proton.me, pm.me, protonmail.ch |
Addresses and aliases | Works on Proton addresses and custom domains. |
| Fastmail | fastmail.com and 100+ Fastmail-owned domains |
Plus addressing and subdomain addressing | Works automatically for all aliases. Full domain list includes fastmail.fm, pobox.com, sent.com, and many more. |
| mailbox.org | mailbox.org |
Using mail extensions | mailbox.org calls this "mail extensions". |
| Yandex Mail | yandex.com, yandex.ru, ya.ru |
Registration (Special email addresses) | Russian provider. Documented under "Special email addresses". |
| Provider | Domains | What it offers instead | Support page |
|---|---|---|---|
| Yahoo Mail | yahoo.com, ymail.com, rocketmail.com |
Temporary/disposable email addresses (must be created first) | Disposable email addresses |
| GMX | gmx.com, gmx.de, gmx.net |
Created alias addresses | Alias Addresses |
| iCloud Mail | icloud.com, me.com, mac.com |
Email aliases and Hide My Email (random relay addresses via iCloud+) | Email aliases / Hide My Email |
| mail.com | mail.com, email.com and 100+ novelty domains |
Up to 10 alias addresses per account | Alias Addresses |
| web.de | web.de |
Alias addresses (premium only) | Absenderadressen |
| T-Online | t-online.de |
Additional email addresses | Zusaetzliche E-Mail-Adresse |
| Tuta (Tutanota) | tuta.com, tutanota.com |
Aliases or custom-domain addresses | How to use Tuta |
| Hey | hey.com |
Aliases only via HEY for Domains | Can I create email aliases? |
| Mail.ru | mail.ru, inbox.ru, list.ru, bk.ru |
Anonymous addresses (up to 10) | Anonymous addresses |
| NetEase | 163.com, 126.com, yeah.net |
NetEase Mail Help | |
| QQ Mail | qq.com, foxmail.com |
Alias accounts (up to 10) | QQ Mail Aliases |
| Libero | libero.it |
Disposable addresses (paid, up to 15/yr) | Indirizzi usa e getta |
| La Poste | laposte.net |
Up to 6 aliases | Gerer mes alias |
| Rediffmail | rediffmail.com, rediff.com |
Rediffmail Help |
| Provider | Domains | Status | Notes |
|---|---|---|---|
| Zoho Mail | zoho.com, custom domains |
Unverified | Community threads indicate name+tag@yourdomain.com may work on custom domains, but no clear official support page was found confirming classic plus addressing. Treated as a custom domain in the extension. |
If you use a custom domain (e.g., @company.com), both modes may be available depending on your email hosting:
- Plus Addressing works if your email host supports sub-addressing (Gmail/Google Workspace, Microsoft 365, Fastmail, etc.)
- Catch-All Prefix works if you have catch-all routing configured on your domain
This table shows which modes are available based on what you enter in the extension settings:
| Input | Plus Addressing | Catch-All Prefix | Reason |
|---|---|---|---|
name@gmail.com |
✅ | ❌ | Gmail supports + |
name@outlook.com |
✅ | ❌ | Outlook supports + |
name@proton.me |
✅ | ❌ | Proton supports + |
name@fastmail.com |
✅ | ❌ | Fastmail supports + |
name@mailbox.org |
✅ | ❌ | mailbox.org supports + |
name@hey.com |
✅ | ❌ | Hey supports + |
name@yahoo.com |
❌ | Yahoo doesn't support + |
|
name@gmx.com |
❌ | GMX doesn't support + |
|
name@icloud.com |
❌ | iCloud doesn't support + |
|
name@mail.com |
❌ | mail.com doesn't support + |
|
name@web.de |
❌ | web.de doesn't support + |
|
name@t-online.de |
❌ | T-Online doesn't support + |
|
name@tuta.com |
❌ | Tuta doesn't support + |
|
name@company.com |
✅ | ✅ | Custom domain, both modes possible |
mydomain.com (no @) |
❌ | ✅ | No local part, only catch-all |
| (empty) | ❌ | ❌ | Nothing configured |
Legend: ✅ Available |
Although + is a valid character in email addresses per RFC 5321, some websites incorrectly reject it during signup or login. Common behaviors:
- Validation error: The form shows "Invalid email address" when
+is present - Silent stripping: The site accepts the email but removes everything from
+to@, soname+site@gmail.combecomesname@gmail.com - Blocking on login: The account was created with
+but the login form rejects it
This is a limitation of the website, not of the email provider or this extension. There is no workaround other than contacting the website or using Catch-All Prefix mode instead.
Gmail ignores dots in the local part: f.i.r.s.t.l.a.s.t@gmail.com is the same as firstlast@gmail.com. This is a Gmail-specific behavior and is not related to plus addressing.
The extension maintains two lists of known email provider domains in src/email/provider-domains.ts. When you enter your email address:
- If the domain matches a known provider that supports
+(Gmail, Outlook, Proton, Fastmail, mailbox.org, Hey) the Plus Addressing column is available and Catch-All is disabled - If the domain matches a known provider without
+support (Yahoo, GMX, iCloud, mail.com, web.de, T-Online, Tuta) the Plus Addressing column shows a warning and Catch-All is disabled - If the domain is not recognized it is treated as a custom domain and both modes are available
- If no
@is present (just a domain) only Catch-All is available