Using mail extensions
Using an unlimited number of email addresses - even without aliases
Our servers support so-called mail extensions – that is, extensions for email addresses. You can use extensions without restriction and free of charge with any mailbox plan.
Extensions offer the following benefits:
- You can use extensions on websites and for third parties as disposable addresses.
- You can track who is passing on your email address.
- You can have all your newsletters or order confirmations sorted automatically into separate folders without filter rules.
- You can keep your inbox tidy and easily separate emails.
Extensions are not aliases and can therefore be used in mailbox Office only to receive emails, but not to send emails. To use an extended email address as a sender address, you must use an email client, e.g. Thunderbird. There, you can use mail extensions as senders in exactly the same way as aliases.
How mail extensions work
You can add as many extensions as you like to the part of your email address that comes before the @ symbol (the local part of your username), separated by a plus sign.
Example: Your email address is me@mailbox.org. You can also receive emails via extensions such as me+test@mailbox.org or me+rssfeed@mailbox.org.
The extensions are ignored by our email servers when sorting emails into mailboxes, so that emails are still assigned to the original email address.
Sorting emails using mail extensions
All emails sent to addresses with extensions are normally placed in your inbox. However, if an (IMAP) folder with the same name exists, emails are automatically sorted into this subfolder without you having to create a separate filter rule – in our example, this would be “test” or “rssfeed”.
Please note the following:
- The relevant IMAP folder must already exist when the email arrives.
- The relevant IMAP folder name must currently contain lowercase letters only.
Example: For instance, you can subscribe to your favourite newsletter at me+newslettername@mailbox.org and then create an (IMAP) folder named “newslettername”.
Other uses for email extensions
If you receive spam or unsolicited advertising via an email address with an extension that you have only used for a particular website or newsletter, you will know immediately who has passed on your address.
Furthermore, when communicating with companies or suspicious recipients, for example, you can add a personalised tag to the email address using the extension, such as me+company@mailbox.org. If you no longer wish to be reachable via this email address at a later date, you can specifically block emails for this exact variant using a filter rule.
Frequently asked questions
Question:
Is it possible to use multiple extensions for an email address, for example firstname.lastname+shopping+company@mailbox.org?
Answer: Yes. Everything after the first plus sign is treated by the Postfix we use as an extension of the base email address. This ensures that every email is delivered to the base email address.
Please note: To have emails in this example automatically sorted into a folder, the name of that folder must be “shopping+company”.
Question: Can I use extensions with aliases instead of the main address only?
Answer: Yes, mail extensions also work with aliases.
Question: Do mail extensions also work if I use the email address of my custom domain?
Answer: Yes, mail extensions also work with email addresses of your custom domain.
