Miscellaneous
Email Alias
What is an email alias?
An email alias is an alternative email address that points to the same mailbox and is easy to manage. You do not need a separate email account. Incoming messages land in the same mailbox, although you can use different addresses externally.
Examples with a Gmail mailbox:
The most common alias variants
| Variant | How it works | Typical use cases |
|---|---|---|
| Custom aliases (e.g., info@yourcompany.ch) | You set up any names in the email provider dashboard that point to your main mailbox. | Company or project addresses, role mailboxes (support@…, sales@…). |
| Catch-all alias (*@yourcompany.ch) | All addresses of a domain that are not explicitly defined are forwarded to a specified mailbox. | Quick test addresses to catch typos. |
| "+" addressing (subaddressing) | The part after the plus sign is ignored by the email server, but remains in the recipient header. | Distinguishing sources like logins, filter rules, tracking data leaks. |
| Hide my email alias | Unique, randomly generated email addresses that are forwarded to your main mailbox. | Protecting your identity, controlling spam, preventing phishing. |
Not every provider supports every variant. Most support custom aliases and catch-all aliases. "+" addressing, on the other hand, is not available everywhere. Hide my email aliases are mostly paid services.
Focus: "+" addressing
How does it work?
The local part of an email address consists of two components:
<local-part>+<tag>
The email server only checks the part before the plus sign (<local-part>).
The tag (<tag>) is ignored but remains in the header – ideal for filter rules, analysis, or for separating logins.
Advantages
- Easy filtering: You can create rules in your mailbox, e.g., "Move all emails to myname+shopping@… to the Shopping folder".
- Identification: Use an alias for the login in customer portals, e.g., for:
- sipcall (max.muster+sipcall@...)
- Swisspass (max.muster+swisspass@...)
- wingo (max.muster+wingo@...)
- etc.
- Tracking data leaks: If a provider publishes your address, you immediately recognize which source caused the leaks.
- No additional accounts: You don't need to create extra aliases; the tag can be chosen freely.
Email aliases are a powerful tool to organize your inbox. "+" addressing offers great convenience because it requires no additional management while allowing precise filtering.
If you have multiple sipcall accounts and do not want to maintain multiple email accounts, you can take advantage of "+" addressing.
For example, with the tag +<phone number>:
- Login for your 1st account:
yourname+0442005000@gmail.com - Login for your 2nd account:
yourname+0324440000@gmail.com
Which email providers support "+" addressing?
It is available with most common email providers – however, check in individual cases whether your desired service supports this function.
We know the following providers*:
- gmail.com (free)
- outlook.com/hotmail.com
- Microsoft Exchange online
- infomaniak (free for one user with kSuite Standard)
- ProtonMail (free)
- iCloud Mail (free)
- Zoho Mail (free with own domain)
- mailbox.org
- posteo.de
*This list is not exhaustive.