Proposal: Limited Catch-All with a Configurable String

[hex-ffffff]

Currently, the Auto create/on the fly alias feature combined with Catch-All is very convenient for dynamically creating aliases. However, this mechanism could be further enhanced to provide even better spam protection.

Instead of accepting emails to any address and automatically creating an alias, SimpleLogin could optionally only accept messages that match a predefined pattern. For instance, each email address must begin with a certain string before the system will treat it as a “Catch-All”:

[prefix][random-part]@domain.com

Or more concretely:

abcweifo3hfe@domain.com
abc98237940@domain.com
adamiofjoiwf@domain.com

Users would define the prefix (e.g., abc, adam, etc.) and the allowed character set (e.g., [a-z,0-9]) for the random part.

Benefits:

• Stronger Spam Protection: Spammers would first need to figure out the prefix required to create aliases. Any email that doesn’t match the correct prefix/pattern is automatically rejected.
• Simplified Organization: By defining a fixed part of the address, it becomes easier to recognize and categorize alias structures. Additionally, you could disable an entire “family” of aliases at once by simply removing the specific prefix.
• Backward Compatibility: Users who prefer the traditional Catch-All can simply leave this feature disabled. Those wanting the additional safeguard can enable the Limited Catch-All pattern.

With such an option, SimpleLogin retains the flexibility of creating on-the-fly aliases while adding an extra, customizable layer of security against spam.

[nguyenkims]

This is already possible with the "auto create" rule that you can define for a custom domain on SL. This auto create rule is based on regular expression and is quite flexible.